This is the multi-page printable view of this section. Click here to print.
Configuration
1 - Configuration
Kafka uses key-value pairs in the property file format for configuration. These values can be supplied either from a file or programmatically.
Broker Configs
The essential configurations are the following:
node.idlog.dirsprocess.rolescontroller.quorum.bootstrap.serversTopic-level configurations and defaults are discussed in more detail below.node.id
The node ID associated with the roles this process is playing when
process.rolesis non-empty. This is required configuration when running in KRaft mode.Type: int Default: Valid Values: [0,...] Importance: high Update Mode: read-only process.roles
The roles that this process plays: 'broker', 'controller', or 'broker,controller' if it is both.
Type: list Default: Valid Values: [broker, controller] Importance: high Update Mode: read-only add.partitions.to.txn.retry.backoff.max.ms
The maximum allowed timeout for adding partitions to transactions on the server side. It only applies to the actual add partition operations, not the verification. It will not be effective if it is larger than request.timeout.ms
Type: int Default: 100 Valid Values: [0,...] Importance: high Update Mode: read-only add.partitions.to.txn.retry.backoff.ms
The server-side retry backoff when the server attemptsto add the partition to the transaction
Type: int Default: 20 Valid Values: [1,...] Importance: high Update Mode: read-only advertised.listeners
Specifies the listener addresses that the Kafka brokers will advertise to clients and other brokers. The config is useful where the actual listener configuration
listenersdoes not represent the addresses that clients should use to connect, such as in cloud environments. The addresses are published to and managed by the controller, the brokers pull these data from the controller as needed. In IaaS environments, this may need to be different from the interface to which the broker binds. If this is not set, the value forlistenerswill be used. Unlikelisteners, it is not valid to advertise the 0.0.0.0 meta-address.
Also unlikelisteners, there can be duplicated ports in this property, so that one listener can be configured to advertise another listener's address. This can be useful in some cases where external load balancers are used.Type: string Default: null Valid Values: Importance: high Update Mode: read-only auto.create.topics.enable
Enable auto creation of topic on the server.
Type: boolean Default: true Valid Values: Importance: high Update Mode: read-only auto.leader.rebalance.enable
Enables auto leader balancing. A background thread checks the distribution of partition leaders at regular intervals, configurable by leader.imbalance.check.interval.seconds. If the leader is imbalanced, leader rebalance to the preferred leader for partitions is triggered.
Type: boolean Default: true Valid Values: Importance: high Update Mode: read-only background.threads
The number of threads to use for various background processing tasks
Type: int Default: 10 Valid Values: [1,...] Importance: high Update Mode: cluster-wide broker.id
The broker id for this server.
Type: int Default: -1 Valid Values: Importance: high Update Mode: read-only compression.type
Specify the final compression type for a given topic. This configuration accepts the standard compression codecs ('gzip', 'snappy', 'lz4', 'zstd'). It additionally accepts 'uncompressed' which is equivalent to no compression; and 'producer' which means retain the original compression codec set by the producer.
Type: string Default: producer Valid Values: [uncompressed, zstd, lz4, snappy, gzip, producer] Importance: high Update Mode: cluster-wide controller.listener.names
A comma-separated list of the names of the listeners used by the controller. This is required when communicating with the controller quorum, the broker will always use the first listener in this list.
Type: string Default: null Valid Values: Importance: high Update Mode: read-only controller.quorum.bootstrap.servers
List of endpoints to use for bootstrapping the cluster metadata. The endpoints are specified in comma-separated list of
{host}:{port}entries. For example:localhost:9092,localhost:9093,localhost:9094.Type: list Default: "" Valid Values: non-empty list Importance: high Update Mode: read-only controller.quorum.election.backoff.max.ms
Maximum time in milliseconds before starting new elections. This is used in the binary exponential backoff mechanism that helps prevent gridlocked elections
Type: int Default: 1000 (1 second) Valid Values: Importance: high Update Mode: read-only controller.quorum.election.timeout.ms
Maximum time in milliseconds to wait without being able to fetch from the leader before triggering a new election
Type: int Default: 1000 (1 second) Valid Values: Importance: high Update Mode: read-only controller.quorum.fetch.timeout.ms
Maximum time without a successful fetch from the current leader before becoming a candidate and triggering an election for voters; Maximum time a leader can go without receiving valid fetch or fetchSnapshot request from a majority of the quorum before resigning.
Type: int Default: 2000 (2 seconds) Valid Values: Importance: high Update Mode: read-only controller.quorum.voters
Map of id/endpoint information for the set of voters in a comma-separated list of
{id}@{host}:{port}entries. For example:1@localhost:9092,2@localhost:9093,3@localhost:9094Type: list Default: "" Valid Values: non-empty list Importance: high Update Mode: read-only delete.topic.enable
Enables delete topic. Delete topic through the admin tool will have no effect if this config is turned off
Type: boolean Default: true Valid Values: Importance: high Update Mode: read-only early.start.listeners
A comma-separated list of listener names which may be started before the authorizer has finished initialization. This is useful when the authorizer is dependent on the cluster itself for bootstrapping, as is the case for the StandardAuthorizer (which stores ACLs in the metadata log.) By default, all listeners included in controller.listener.names will also be early start listeners. A listener should not appear in this list if it accepts external traffic.
Type: string Default: null Valid Values: Importance: high Update Mode: read-only group.coordinator.threads
The number of threads used by the group coordinator.
Type: int Default: 4 Valid Values: [1,...] Importance: high Update Mode: read-only leader.imbalance.check.interval.seconds
The frequency with which the partition rebalance check is triggered by the controller
Type: long Default: 300 Valid Values: [1,...] Importance: high Update Mode: read-only listeners
Listener List - Comma-separated list of URIs we will listen on and the listener names. If the listener name is not a security protocol,
listener.security.protocol.mapmust also be set.
Listener names and port numbers must be unique unless one listener is an IPv4 address and the other listener is an IPv6 address (for the same port).
Specify hostname as 0.0.0.0 to bind to all interfaces.
Leave hostname empty to bind to default interface.
Examples of legal listener lists:PLAINTEXT://myhost:9092,SSL://:9091CLIENT://0.0.0.0:9092,REPLICATION://localhost:9093PLAINTEXT://127.0.0.1:9092,SSL://[::1]:9092Type: string Default: PLAINTEXT://:9092 Valid Values: Importance: high Update Mode: per-broker log.dir
The directory in which the log data is kept (supplemental for log.dirs property)
Type: string Default: /tmp/kafka-logs Valid Values: Importance: high Update Mode: read-only log.dirs
A comma-separated list of the directories where the log data is stored. If not set, the value in log.dir is used.
Type: string Default: null Valid Values: Importance: high Update Mode: read-only log.flush.interval.messages
The number of messages accumulated on a log partition before messages are flushed to disk.
Type: long Default: 9223372036854775807 Valid Values: [1,...] Importance: high Update Mode: cluster-wide log.flush.interval.ms
The maximum time in ms that a message in any topic is kept in memory before flushed to disk. If not set, the value in log.flush.scheduler.interval.ms is used
Type: long Default: null Valid Values: Importance: high Update Mode: cluster-wide log.flush.offset.checkpoint.interval.ms
The frequency with which we update the persistent record of the last flush which acts as the log recovery point.
Type: int Default: 60000 (1 minute) Valid Values: [0,...] Importance: high Update Mode: read-only log.flush.scheduler.interval.ms
The frequency in ms that the log flusher checks whether any log needs to be flushed to disk
Type: long Default: 9223372036854775807 Valid Values: Importance: high Update Mode: read-only log.flush.start.offset.checkpoint.interval.ms
The frequency with which we update the persistent record of log start offset
Type: int Default: 60000 (1 minute) Valid Values: [0,...] Importance: high Update Mode: read-only log.retention.bytes
The maximum size of the log before deleting it
Type: long Default: -1 Valid Values: Importance: high Update Mode: cluster-wide log.retention.hours
The number of hours to keep a log file before deleting it (in hours), tertiary to log.retention.ms property
Type: int Default: 168 Valid Values: Importance: high Update Mode: read-only log.retention.minutes
The number of minutes to keep a log file before deleting it (in minutes), secondary to log.retention.ms property. If not set, the value in log.retention.hours is used
Type: int Default: null Valid Values: Importance: high Update Mode: read-only log.retention.ms
The number of milliseconds to keep a log file before deleting it (in milliseconds), If not set, the value in log.retention.minutes is used. If set to -1, no time limit is applied.
Type: long Default: null Valid Values: Importance: high Update Mode: cluster-wide log.roll.hours
The maximum time before a new log segment is rolled out (in hours), secondary to log.roll.ms property
Type: int Default: 168 Valid Values: [1,...] Importance: high Update Mode: read-only log.roll.jitter.hours
The maximum jitter to subtract from logRollTimeMillis (in hours), secondary to log.roll.jitter.ms property
Type: int Default: 0 Valid Values: [0,...] Importance: high Update Mode: read-only log.roll.jitter.ms
The maximum jitter to subtract from logRollTimeMillis (in milliseconds). If not set, the value in log.roll.jitter.hours is used
Type: long Default: null Valid Values: Importance: high Update Mode: cluster-wide log.roll.ms
The maximum time before a new log segment is rolled out (in milliseconds). If not set, the value in log.roll.hours is used
Type: long Default: null Valid Values: Importance: high Update Mode: cluster-wide log.segment.bytes
The maximum size of a single log file
Type: int Default: 1073741824 (1 gibibyte) Valid Values: [1048576,...] Importance: high Update Mode: cluster-wide log.segment.delete.delay.ms
The amount of time to wait before deleting a file from the filesystem. If the value is 0 and there is no file to delete, the system will wait 1 millisecond. Low value will cause busy waiting
Type: long Default: 60000 (1 minute) Valid Values: [0,...] Importance: high Update Mode: cluster-wide message.max.bytes
The largest record batch size allowed by Kafka (after compression if compression is enabled). If this is increased and there are consumers older than 0.10.2, the consumers' fetch size must also be increased so that they can fetch record batches this large. In the latest message format version, records are always grouped into batches for efficiency. In previous message format versions, uncompressed records are not grouped into batches and this limit only applies to a single record in that case.This can be set per topic with the topic level
max.message.bytesconfig.Type: int Default: 1048588 Valid Values: [0,...] Importance: high Update Mode: cluster-wide metadata.log.dir
This configuration determines where we put the metadata log. If it is not set, the metadata log is placed in the first log directory from log.dirs.
Type: string Default: null Valid Values: Importance: high Update Mode: read-only metadata.log.max.record.bytes.between.snapshots
This is the maximum number of bytes in the log between the latest snapshot and the high-watermark needed before generating a new snapshot. The default value is 20971520. To generate snapshots based on the time elapsed, see the
metadata.log.max.snapshot.interval.msconfiguration. The Kafka node will generate a snapshot when either the maximum time interval is reached or the maximum bytes limit is reached.Type: long Default: 20971520 Valid Values: [1,...] Importance: high Update Mode: read-only metadata.log.max.snapshot.interval.ms
This is the maximum number of milliseconds to wait to generate a snapshot if there are committed records in the log that are not included in the latest snapshot. A value of zero disables time based snapshot generation. The default value is 3600000. To generate snapshots based on the number of metadata bytes, see the
metadata.log.max.record.bytes.between.snapshotsconfiguration. The Kafka node will generate a snapshot when either the maximum time interval is reached or the maximum bytes limit is reached.Type: long Default: 3600000 (1 hour) Valid Values: [0,...] Importance: high Update Mode: read-only metadata.log.segment.bytes
The maximum size of a single metadata log file.
Type: int Default: 1073741824 (1 gibibyte) Valid Values: [12,...] Importance: high Update Mode: read-only metadata.log.segment.ms
The maximum time before a new metadata log file is rolled out (in milliseconds).
Type: long Default: 604800000 (7 days) Valid Values: Importance: high Update Mode: read-only metadata.max.retention.bytes
The maximum combined size of the metadata log and snapshots before deleting old snapshots and log files. Since at least one snapshot must exist before any logs can be deleted, this is a soft limit.
Type: long Default: 104857600 (100 mebibytes) Valid Values: Importance: high Update Mode: read-only metadata.max.retention.ms
The number of milliseconds to keep a metadata log file or snapshot before deleting it. Since at least one snapshot must exist before any logs can be deleted, this is a soft limit.
Type: long Default: 604800000 (7 days) Valid Values: Importance: high Update Mode: read-only min.insync.replicas
When a producer sets acks to "all" (or "-1"), this configuration specifies the minimum number of replicas that must acknowledge a write for the write to be considered successful. If this minimum cannot be met, then the producer will raise an exception (either
NotEnoughReplicasorNotEnoughReplicasAfterAppend).
Regardless of theackssetting, the messages will not be visible to the consumers until they are replicated to all in-sync replicas and themin.insync.replicascondition is met.
When used together,min.insync.replicasandacksallow you to enforce greater durability guarantees. A typical scenario would be to create a topic with a replication factor of 3, setmin.insync.replicasto 2, and produce withacksof "all". This will ensure that a majority of replicas must persist a write before it's considered successful by the producer and it's visible to consumers.Type: int Default: 1 Valid Values: [1,...] Importance: high Update Mode: cluster-wide num.io.threads
The number of threads that the server uses for processing requests, which may include disk I/O
Type: int Default: 8 Valid Values: [1,...] Importance: high Update Mode: cluster-wide num.network.threads
The number of threads that the server uses for receiving requests from the network and sending responses to the network. Noted: each listener (except for controller listener) creates its own thread pool.
Type: int Default: 3 Valid Values: [1,...] Importance: high Update Mode: cluster-wide num.recovery.threads.per.data.dir
The number of threads per data directory to be used for log recovery at startup and flushing at shutdown
Type: int Default: 2 Valid Values: [1,...] Importance: high Update Mode: cluster-wide num.replica.alter.log.dirs.threads
The number of threads that can move replicas between log directories, which may include disk I/O. The default value is equal to the number of directories specified in the
log.dirorlog.dirsconfiguration property.Type: int Default: null Valid Values: Importance: high Update Mode: read-only num.replica.fetchers
Number of fetcher threads used to replicate records from each source broker. The total number of fetchers on each broker is bound by
num.replica.fetchersmultiplied by the number of brokers in the cluster.Increasing this value can increase the degree of I/O parallelism in the follower and leader broker at the cost of higher CPU and memory utilization.Type: int Default: 1 Valid Values: Importance: high Update Mode: cluster-wide offset.metadata.max.bytes
The maximum size for a metadata entry associated with an offset commit.
Type: int Default: 4096 (4 kibibytes) Valid Values: Importance: high Update Mode: read-only offsets.commit.timeout.ms
Offset commit will be delayed until all replicas for the offsets topic receive the commit or this timeout is reached. This is similar to the producer request timeout. This is applied to all the writes made by the coordinator.
Type: int Default: 5000 (5 seconds) Valid Values: [1,...] Importance: high Update Mode: read-only offsets.load.buffer.size
Batch size for reading from the offsets segments when loading group metadata into the cache (soft-limit, overridden if records are too large).
Type: int Default: 5242880 Valid Values: [1,...] Importance: high Update Mode: read-only offsets.retention.check.interval.ms
Frequency at which to check for stale offsets
Type: long Default: 600000 (10 minutes) Valid Values: [1,...] Importance: high Update Mode: read-only offsets.retention.minutes
For subscribed consumers, committed offset of a specific partition will be expired and discarded when 1) this retention period has elapsed after the consumer group loses all its consumers (i.e. becomes empty); 2) this retention period has elapsed since the last time an offset is committed for the partition and the group is no longer subscribed to the corresponding topic. For standalone consumers (using manual assignment), offsets will be expired after this retention period has elapsed since the time of last commit. Note that when a group is deleted via the delete-group request, its committed offsets will also be deleted without extra retention period; also when a topic is deleted via the delete-topic request, upon propagated metadata update any group's committed offsets for that topic will also be deleted without extra retention period.
Type: int Default: 10080 Valid Values: [1,...] Importance: high Update Mode: read-only offsets.topic.compression.codec
Compression codec for the offsets topic - compression may be used to achieve "atomic" commits.
Type: int Default: 0 Valid Values: Importance: high Update Mode: read-only offsets.topic.num.partitions
The number of partitions for the offset commit topic (should not change after deployment).
Type: int Default: 50 Valid Values: [1,...] Importance: high Update Mode: read-only offsets.topic.replication.factor
The replication factor for the offsets topic (set higher to ensure availability). Internal topic creation will fail until the cluster size meets this replication factor requirement.
Type: short Default: 3 Valid Values: [1,...] Importance: high Update Mode: read-only offsets.topic.segment.bytes
The offsets topic segment bytes should be kept relatively small in order to facilitate faster log compaction and cache loads.
Type: int Default: 104857600 (100 mebibytes) Valid Values: [1,...] Importance: high Update Mode: read-only queued.max.requests
The number of queued requests allowed for data-plane, before blocking the network threads
Type: int Default: 500 Valid Values: [1,...] Importance: high Update Mode: read-only replica.fetch.min.bytes
Minimum bytes expected for each fetch response. If not enough bytes, wait up to
replica.fetch.wait.max.ms(broker config).Type: int Default: 1 Valid Values: Importance: high Update Mode: read-only replica.fetch.wait.max.ms
The maximum wait time for each fetcher request issued by follower replicas. This value should always be less than the replica.lag.time.max.ms at all times to prevent frequent shrinking of ISR for low throughput topics
Type: int Default: 500 Valid Values: Importance: high Update Mode: read-only replica.high.watermark.checkpoint.interval.ms
The frequency with which the high watermark is saved out to disk
Type: long Default: 5000 (5 seconds) Valid Values: Importance: high Update Mode: read-only replica.lag.time.max.ms
If a follower hasn't sent any fetch requests or hasn't consumed up to the leader's log end offset for at least this time, the leader will remove the follower from ISR
Type: long Default: 30000 (30 seconds) Valid Values: Importance: high Update Mode: read-only replica.socket.receive.buffer.bytes
The socket receive buffer for network requests to the leader for replicating data
Type: int Default: 65536 (64 kibibytes) Valid Values: Importance: high Update Mode: read-only replica.socket.timeout.ms
The socket timeout for network requests. Its value should be at least replica.fetch.wait.max.ms
Type: int Default: 30000 (30 seconds) Valid Values: Importance: high Update Mode: read-only request.timeout.ms
The configuration controls the maximum amount of time the client will wait for the response of a request. If the response is not received before the timeout elapses the client will resend the request if necessary or fail the request if retries are exhausted.
Type: int Default: 30000 (30 seconds) Valid Values: Importance: high Update Mode: read-only sasl.mechanism.controller.protocol
SASL mechanism used for communication with controllers. Default is GSSAPI.
Type: string Default: GSSAPI Valid Values: Importance: high Update Mode: read-only share.coordinator.load.buffer.size
Batch size for reading from the share-group state topic when loading state information into the cache (soft-limit, overridden if records are too large).
Type: int Default: 5242880 Valid Values: [1,...] Importance: high Update Mode: read-only share.coordinator.state.topic.compression.codec
Compression codec for the share-group state topic.
Type: int Default: 0 Valid Values: Importance: high Update Mode: read-only share.coordinator.state.topic.min.isr
Overridden min.insync.replicas for the share-group state topic.
Type: short Default: 2 Valid Values: [1,...] Importance: high Update Mode: read-only share.coordinator.state.topic.num.partitions
The number of partitions for the share-group state topic (should not change after deployment).
Type: int Default: 50 Valid Values: [1,...] Importance: high Update Mode: read-only share.coordinator.state.topic.replication.factor
Replication factor for the share-group state topic. Topic creation will fail until the cluster size meets this replication factor requirement.
Type: short Default: 3 Valid Values: [1,...] Importance: high Update Mode: read-only share.coordinator.state.topic.segment.bytes
The log segment size for the share-group state topic.
Type: int Default: 104857600 (100 mebibytes) Valid Values: [1,...] Importance: high Update Mode: read-only share.coordinator.write.timeout.ms
The duration in milliseconds that the share coordinator will wait for all replicas of the share-group state topic to receive a write.
Type: int Default: 5000 (5 seconds) Valid Values: [1,...] Importance: high Update Mode: read-only socket.receive.buffer.bytes
The SO_RCVBUF buffer of the socket server sockets. If the value is -1, the OS default will be used.
Type: int Default: 102400 (100 kibibytes) Valid Values: Importance: high Update Mode: read-only socket.request.max.bytes
The maximum number of bytes in a socket request
Type: int Default: 104857600 (100 mebibytes) Valid Values: [1,...] Importance: high Update Mode: read-only socket.send.buffer.bytes
The SO_SNDBUF buffer of the socket server sockets. If the value is -1, the OS default will be used.
Type: int Default: 102400 (100 kibibytes) Valid Values: Importance: high Update Mode: read-only transaction.max.timeout.ms
The maximum allowed timeout for transactions. If a client’s requested transaction time exceed this, then the broker will return an error in InitProducerIdRequest. This prevents a client from too large of a timeout, which can stall consumers reading from topics included in the transaction.
Type: int Default: 900000 (15 minutes) Valid Values: [1,...] Importance: high Update Mode: read-only transaction.state.log.load.buffer.size
Batch size for reading from the transaction log segments when loading producer ids and transactions into the cache (soft-limit, overridden if records are too large).
Type: int Default: 5242880 Valid Values: [1,...] Importance: high Update Mode: read-only transaction.state.log.min.isr
The minimum number of replicas that must acknowledge a write to transaction topic in order to be considered successful.
Type: int Default: 2 Valid Values: [1,...] Importance: high Update Mode: read-only transaction.state.log.num.partitions
The number of partitions for the transaction topic (should not change after deployment).
Type: int Default: 50 Valid Values: [1,...] Importance: high Update Mode: read-only transaction.state.log.replication.factor
The replication factor for the transaction topic (set higher to ensure availability). Internal topic creation will fail until the cluster size meets this replication factor requirement.
Type: short Default: 3 Valid Values: [1,...] Importance: high Update Mode: read-only transaction.state.log.segment.bytes
The transaction topic segment bytes should be kept relatively small in order to facilitate faster log compaction and cache loads
Type: int Default: 104857600 (100 mebibytes) Valid Values: [1,...] Importance: high Update Mode: read-only transactional.id.expiration.ms
The time in ms that the transaction coordinator will wait without receiving any transaction status updates for the current transaction before expiring its transactional id. Transactional IDs will not expire while a the transaction is still ongoing.
Type: int Default: 604800000 (7 days) Valid Values: [1,...] Importance: high Update Mode: read-only unclean.leader.election.enable
Indicates whether to enable replicas not in the ISR set to be elected as leader as a last resort, even though doing so may result in data loss
Note: In KRaft mode, when enabling this config dynamically, it needs to wait for the unclean leader election thread to trigger election periodically (default is 5 minutes). Please run `kafka-leader-election.sh` with `unclean` option to trigger the unclean leader election immediately if needed.
Type: boolean Default: false Valid Values: Importance: high Update Mode: cluster-wide broker.heartbeat.interval.ms
The length of time in milliseconds between broker heartbeats.
Type: int Default: 2000 (2 seconds) Valid Values: Importance: medium Update Mode: read-only broker.rack
Rack of the broker. This will be used in rack aware replication assignment for fault tolerance. Examples:
RACK1,us-east-1dType: string Default: null Valid Values: Importance: medium Update Mode: read-only broker.session.timeout.ms
The length of time in milliseconds that a broker lease lasts if no heartbeats are made.
Type: int Default: 9000 (9 seconds) Valid Values: Importance: medium Update Mode: read-only compression.gzip.level
The compression level to use if compression.type is set to 'gzip'.
Type: int Default: -1 Valid Values: [1,...,9] or -1 Importance: medium Update Mode: cluster-wide compression.lz4.level
The compression level to use if compression.type is set to 'lz4'.
Type: int Default: 9 Valid Values: [1,...,17] Importance: medium Update Mode: cluster-wide compression.zstd.level
The compression level to use if compression.type is set to 'zstd'.
Type: int Default: 3 Valid Values: [-131072,...,22] Importance: medium Update Mode: cluster-wide connections.max.idle.ms
Idle connections timeout: the server socket processor threads close the connections that idle more than this
Type: long Default: 600000 (10 minutes) Valid Values: Importance: medium Update Mode: read-only connections.max.reauth.ms
When explicitly set to a positive number (the default is 0, not a positive number), a session lifetime that will not exceed the configured value will be communicated to v2.2.0 or later clients when they authenticate. The broker will disconnect any such connection that is not re-authenticated within the session lifetime and that is then subsequently used for any purpose other than re-authentication. Configuration names can optionally be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.oauthbearer.connections.max.reauth.ms=3600000
Type: long Default: 0 Valid Values: Importance: medium Update Mode: read-only controlled.shutdown.enable
Enable controlled shutdown of the server.
Type: boolean Default: true Valid Values: Importance: medium Update Mode: read-only controller.quorum.append.linger.ms
The duration in milliseconds that the leader will wait for writes to accumulate before flushing them to disk.
Type: int Default: 25 Valid Values: Importance: medium Update Mode: read-only controller.quorum.request.timeout.ms
The configuration controls the maximum amount of time the client will wait for the response of a request. If the response is not received before the timeout elapses the client will resend the request if necessary or fail the request if retries are exhausted.
Type: int Default: 2000 (2 seconds) Valid Values: Importance: medium Update Mode: read-only controller.socket.timeout.ms
The socket timeout for controller-to-broker channels.
Type: int Default: 30000 (30 seconds) Valid Values: Importance: medium Update Mode: read-only default.replication.factor
The replication factor for automatically created topics, and for topics created with -1 as the replication factor
Type: int Default: 1 Valid Values: Importance: medium Update Mode: read-only delegation.token.expiry.time.ms
The token validity time in milliseconds before the token needs to be renewed. Default value 1 day.
Type: long Default: 86400000 (1 day) Valid Values: [1,...] Importance: medium Update Mode: read-only delegation.token.max.lifetime.ms
The token has a maximum lifetime beyond which it cannot be renewed anymore. Default value 7 days.
Type: long Default: 604800000 (7 days) Valid Values: [1,...] Importance: medium Update Mode: read-only delegation.token.secret.key
Secret key to generate and verify delegation tokens. The same key must be configured across all the brokers. If using Kafka with KRaft, the key must also be set across all controllers. If the key is not set or set to empty string, brokers will disable the delegation token support.
Type: password Default: null Valid Values: Importance: medium Update Mode: read-only delete.records.purgatory.purge.interval.requests
The purge interval (in number of requests) of the delete records request purgatory
Type: int Default: 1 Valid Values: Importance: medium Update Mode: read-only fetch.max.bytes
The maximum number of bytes we will return for a fetch request. Must be at least 1024.
Type: int Default: 57671680 (55 mebibytes) Valid Values: [1024,...] Importance: medium Update Mode: read-only fetch.purgatory.purge.interval.requests
The purge interval (in number of requests) of the fetch request purgatory
Type: int Default: 1000 Valid Values: Importance: medium Update Mode: read-only group.consumer.assignors
The server side assignors as a list of either names for builtin assignors or full class names for customer assignors. The first one in the list is considered as the default assignor to be used in the case where the consumer does not specify an assignor. The supported builtin assignors are: uniform, range.
Type: list Default: uniform,range Valid Values: Importance: medium Update Mode: read-only group.consumer.heartbeat.interval.ms
The heartbeat interval given to the members of a consumer group.
Type: int Default: 5000 (5 seconds) Valid Values: [1,...] Importance: medium Update Mode: read-only group.consumer.max.heartbeat.interval.ms
The maximum heartbeat interval for registered consumers.
Type: int Default: 15000 (15 seconds) Valid Values: [1,...] Importance: medium Update Mode: read-only group.consumer.max.session.timeout.ms
The maximum allowed session timeout for registered consumers.
Type: int Default: 60000 (1 minute) Valid Values: [1,...] Importance: medium Update Mode: read-only group.consumer.max.size
The maximum number of consumers that a single consumer group can accommodate. This value will only impact groups under the CONSUMER group protocol. To configure the max group size when using the CLASSIC group protocol use group.max.size instead.
Type: int Default: 2147483647 Valid Values: [1,...] Importance: medium Update Mode: read-only group.consumer.migration.policy
The config that enables converting the non-empty classic group using the consumer embedded protocol to the non-empty consumer group using the consumer group protocol and vice versa; conversions of empty groups in both directions are always enabled regardless of this policy. bidirectional: both upgrade from classic group to consumer group and downgrade from consumer group to classic group are enabled, upgrade: only upgrade from classic group to consumer group is enabled, downgrade: only downgrade from consumer group to classic group is enabled, disabled: neither upgrade nor downgrade is enabled.
Type: string Default: bidirectional Valid Values: (case insensitive) [DISABLED, DOWNGRADE, UPGRADE, BIDIRECTIONAL] Importance: medium Update Mode: read-only group.consumer.min.heartbeat.interval.ms
The minimum heartbeat interval for registered consumers.
Type: int Default: 5000 (5 seconds) Valid Values: [1,...] Importance: medium Update Mode: read-only group.consumer.min.session.timeout.ms
The minimum allowed session timeout for registered consumers.
Type: int Default: 45000 (45 seconds) Valid Values: [1,...] Importance: medium Update Mode: read-only group.consumer.session.timeout.ms
The timeout to detect client failures when using the consumer group protocol.
Type: int Default: 45000 (45 seconds) Valid Values: [1,...] Importance: medium Update Mode: read-only group.coordinator.append.linger.ms
The duration in milliseconds that the coordinator will wait for writes to accumulate before flushing them to disk. Transactional writes are not accumulated.
Type: int Default: 5 Valid Values: [0,...] Importance: medium Update Mode: read-only group.coordinator.rebalance.protocols
The list of enabled rebalance protocols.The share rebalance protocol is in early access and therefore must not be used in production.
Type: list Default: classic,consumer Valid Values: [consumer, classic, share] Importance: medium Update Mode: read-only group.initial.rebalance.delay.ms
The amount of time the group coordinator will wait for more consumers to join a new group before performing the first rebalance. A longer delay means potentially fewer rebalances, but increases the time until processing begins.
Type: int Default: 3000 (3 seconds) Valid Values: Importance: medium Update Mode: read-only group.max.session.timeout.ms
The maximum allowed session timeout for registered consumers. Longer timeouts give consumers more time to process messages in between heartbeats at the cost of a longer time to detect failures.
Type: int Default: 1800000 (30 minutes) Valid Values: Importance: medium Update Mode: read-only group.max.size
The maximum number of consumers that a single consumer group can accommodate.
Type: int Default: 2147483647 Valid Values: [1,...] Importance: medium Update Mode: read-only group.min.session.timeout.ms
The minimum allowed session timeout for registered consumers. Shorter timeouts result in quicker failure detection at the cost of more frequent consumer heartbeating, which can overwhelm broker resources.
Type: int Default: 6000 (6 seconds) Valid Values: Importance: medium Update Mode: read-only group.share.delivery.count.limit
The maximum number of delivery attempts for a record delivered to a share group.
Type: int Default: 5 Valid Values: [2,...,10] Importance: medium Update Mode: read-only group.share.heartbeat.interval.ms
The heartbeat interval given to the members of a share group.
Type: int Default: 5000 (5 seconds) Valid Values: [1,...] Importance: medium Update Mode: read-only group.share.max.groups
The maximum number of share groups.
Type: short Default: 10 Valid Values: [1,...,100] Importance: medium Update Mode: read-only group.share.max.heartbeat.interval.ms
The maximum heartbeat interval for share group members.
Type: int Default: 15000 (15 seconds) Valid Values: [1,...] Importance: medium Update Mode: read-only group.share.max.record.lock.duration.ms
The record acquisition lock maximum duration in milliseconds for share groups.
Type: int Default: 60000 (1 minute) Valid Values: [30000,...,3600000] Importance: medium Update Mode: read-only group.share.max.session.timeout.ms
The maximum allowed session timeout for share group members.
Type: int Default: 60000 (1 minute) Valid Values: [1,...] Importance: medium Update Mode: read-only group.share.max.size
The maximum number of members that a single share group can accommodate.
Type: int Default: 200 Valid Values: [1,...,1000] Importance: medium Update Mode: read-only group.share.min.heartbeat.interval.ms
The minimum heartbeat interval for share group members.
Type: int Default: 5000 (5 seconds) Valid Values: [1,...] Importance: medium Update Mode: read-only group.share.min.record.lock.duration.ms
The record acquisition lock minimum duration in milliseconds for share groups.
Type: int Default: 15000 (15 seconds) Valid Values: [1000,...,30000] Importance: medium Update Mode: read-only group.share.min.session.timeout.ms
The minimum allowed session timeout for share group members.
Type: int Default: 45000 (45 seconds) Valid Values: [1,...] Importance: medium Update Mode: read-only group.share.partition.max.record.locks
Share-group record lock limit per share-partition.
Type: int Default: 200 Valid Values: [100,...,10000] Importance: medium Update Mode: read-only group.share.record.lock.duration.ms
The record acquisition lock duration in milliseconds for share groups.
Type: int Default: 30000 (30 seconds) Valid Values: [1000,...,3600000] Importance: medium Update Mode: read-only group.share.session.timeout.ms
The timeout to detect client failures when using the share group protocol.
Type: int Default: 45000 (45 seconds) Valid Values: [1,...] Importance: medium Update Mode: read-only initial.broker.registration.timeout.ms
When initially registering with the controller quorum, the number of milliseconds to wait before declaring failure and exiting the broker process.
Type: int Default: 60000 (1 minute) Valid Values: Importance: medium Update Mode: read-only inter.broker.listener.name
Name of listener used for communication between brokers. If this is unset, the listener name is defined by security.inter.broker.protocol. It is an error to set this and security.inter.broker.protocol properties at the same time.
Type: string Default: null Valid Values: Importance: medium Update Mode: read-only log.cleaner.backoff.ms
The amount of time to sleep when there are no logs to clean
Type: long Default: 15000 (15 seconds) Valid Values: [0,...] Importance: medium Update Mode: cluster-wide log.cleaner.dedupe.buffer.size
The total memory used for log deduplication across all cleaner threads
Type: long Default: 134217728 Valid Values: Importance: medium Update Mode: cluster-wide log.cleaner.delete.retention.ms
The amount of time to retain tombstone message markers for log compacted topics. This setting also gives a bound on the time in which a consumer must complete a read if they begin from offset 0 to ensure that they get a valid snapshot of the final stage (otherwise tombstones messages may be collected before a consumer completes their scan).
Type: long Default: 86400000 (1 day) Valid Values: [0,...] Importance: medium Update Mode: cluster-wide log.cleaner.enable
Enable the log cleaner process to run on the server. Should be enabled if using any topics with a cleanup.policy=compact including the internal offsets topic. If disabled those topics will not be compacted and continually grow in size.
Type: boolean Default: true Valid Values: Importance: medium Update Mode: read-only log.cleaner.io.buffer.load.factor
Log cleaner dedupe buffer load factor. The percentage full the dedupe buffer can become. A higher value will allow more log to be cleaned at once but will lead to more hash collisions
Type: double Default: 0.9 Valid Values: Importance: medium Update Mode: cluster-wide log.cleaner.io.buffer.size
The total memory used for log cleaner I/O buffers across all cleaner threads
Type: int Default: 524288 Valid Values: [0,...] Importance: medium Update Mode: cluster-wide log.cleaner.io.max.bytes.per.second
The log cleaner will be throttled so that the sum of its read and write i/o will be less than this value on average
Type: double Default: 1.7976931348623157E308 Valid Values: Importance: medium Update Mode: cluster-wide log.cleaner.max.compaction.lag.ms
The maximum time a message will remain ineligible for compaction in the log. Only applicable for logs that are being compacted.
Type: long Default: 9223372036854775807 Valid Values: [1,...] Importance: medium Update Mode: cluster-wide log.cleaner.min.cleanable.ratio
The minimum ratio of dirty log to total log for a log to eligible for cleaning. If the log.cleaner.max.compaction.lag.ms or the log.cleaner.min.compaction.lag.ms configurations are also specified, then the log compactor considers the log eligible for compaction as soon as either: (i) the dirty ratio threshold has been met and the log has had dirty (uncompacted) records for at least the log.cleaner.min.compaction.lag.ms duration, or (ii) if the log has had dirty (uncompacted) records for at most the log.cleaner.max.compaction.lag.ms period.
Type: double Default: 0.5 Valid Values: [0,...,1] Importance: medium Update Mode: cluster-wide log.cleaner.min.compaction.lag.ms
The minimum time a message will remain uncompacted in the log. Only applicable for logs that are being compacted.
Type: long Default: 0 Valid Values: [0,...] Importance: medium Update Mode: cluster-wide log.cleaner.threads
The number of background threads to use for log cleaning
Type: int Default: 1 Valid Values: [0,...] Importance: medium Update Mode: cluster-wide log.cleanup.policy
The default cleanup policy for segments beyond the retention window. A comma separated list of valid policies.
Type: list Default: delete Valid Values: [compact, delete] Importance: medium Update Mode: cluster-wide log.index.interval.bytes
The interval with which we add an entry to the offset index.
Type: int Default: 4096 (4 kibibytes) Valid Values: [0,...] Importance: medium Update Mode: cluster-wide log.index.size.max.bytes
The maximum size in bytes of the offset index
Type: int Default: 10485760 (10 mebibytes) Valid Values: [4,...] Importance: medium Update Mode: cluster-wide log.local.retention.bytes
The maximum size of local log segments that can grow for a partition before it gets eligible for deletion. Default value is -2, it represents `log.retention.bytes` value to be used. The effective value should always be less than or equal to `log.retention.bytes` value.
Type: long Default: -2 Valid Values: [-2,...] Importance: medium Update Mode: cluster-wide log.local.retention.ms
The number of milliseconds to keep the local log segments before it gets eligible for deletion. Default value is -2, it represents `log.retention.ms` value is to be used. The effective value should always be less than or equal to `log.retention.ms` value.
Type: long Default: -2 Valid Values: [-2,...] Importance: medium Update Mode: cluster-wide log.message.timestamp.after.max.ms
This configuration sets the allowable timestamp difference between the message timestamp and the broker's timestamp. The message timestamp can be later than or equal to the broker's timestamp, with the maximum allowable difference determined by the value set in this configuration. If log.message.timestamp.type=CreateTime, the message will be rejected if the difference in timestamps exceeds this specified threshold. This configuration is ignored if log.message.timestamp.type=LogAppendTime.
Type: long Default: 3600000 (1 hour) Valid Values: [0,...] Importance: medium Update Mode: cluster-wide log.message.timestamp.before.max.ms
This configuration sets the allowable timestamp difference between the broker's timestamp and the message timestamp. The message timestamp can be earlier than or equal to the broker's timestamp, with the maximum allowable difference determined by the value set in this configuration. If log.message.timestamp.type=CreateTime, the message will be rejected if the difference in timestamps exceeds this specified threshold. This configuration is ignored if log.message.timestamp.type=LogAppendTime.
Type: long Default: 9223372036854775807 Valid Values: [0,...] Importance: medium Update Mode: cluster-wide log.message.timestamp.type
Define whether the timestamp in the message is message create time or log append time. The value should be either
CreateTimeorLogAppendTime.Type: string Default: CreateTime Valid Values: [CreateTime, LogAppendTime] Importance: medium Update Mode: cluster-wide log.preallocate
Should pre allocate file when create new segment? If you are using Kafka on Windows, you probably need to set it to true.
Type: boolean Default: false Valid Values: Importance: medium Update Mode: cluster-wide log.retention.check.interval.ms
The frequency in milliseconds that the log cleaner checks whether any log is eligible for deletion
Type: long Default: 300000 (5 minutes) Valid Values: [1,...] Importance: medium Update Mode: read-only max.connection.creation.rate
The maximum connection creation rate we allow in the broker at any time. Listener-level limits may also be configured by prefixing the config name with the listener prefix, for example,
listener.name.internal.max.connection.creation.rate.Broker-wide connection rate limit should be configured based on broker capacity while listener limits should be configured based on application requirements. New connections will be throttled if either the listener or the broker limit is reached, with the exception of inter-broker listener. Connections on the inter-broker listener will be throttled only when the listener-level rate limit is reached.Type: int Default: 2147483647 Valid Values: [0,...] Importance: medium Update Mode: cluster-wide max.connections
The maximum number of connections we allow in the broker at any time. This limit is applied in addition to any per-ip limits configured using max.connections.per.ip. Listener-level limits may also be configured by prefixing the config name with the listener prefix, for example,
listener.name.internal.max.connections.per.ip. Broker-wide limit should be configured based on broker capacity while listener limits should be configured based on application requirements. New connections are blocked if either the listener or broker limit is reached. Connections on the inter-broker listener are permitted even if broker-wide limit is reached. The least recently used connection on another listener will be closed in this case.Type: int Default: 2147483647 Valid Values: [0,...] Importance: medium Update Mode: cluster-wide max.connections.per.ip
The maximum number of connections we allow from each ip address. This can be set to 0 if there are overrides configured using max.connections.per.ip.overrides property. New connections from the ip address are dropped if the limit is reached.
Type: int Default: 2147483647 Valid Values: [0,...] Importance: medium Update Mode: cluster-wide max.connections.per.ip.overrides
A comma-separated list of per-ip or hostname overrides to the default maximum number of connections. An example value is "hostName:100,127.0.0.1:200"
Type: string Default: "" Valid Values: Importance: medium Update Mode: cluster-wide max.incremental.fetch.session.cache.slots
The maximum number of total incremental fetch sessions that we will maintain. FetchSessionCache is sharded into 8 shards and the limit is equally divided among all shards. Sessions are allocated to each shard in round-robin. Only entries within a shard are considered eligible for eviction.
Type: int Default: 1000 Valid Values: [0,...] Importance: medium Update Mode: read-only max.request.partition.size.limit
The maximum number of partitions can be served in one request.
Type: int Default: 2000 Valid Values: [1,...] Importance: medium Update Mode: read-only num.partitions
The default number of log partitions per topic
Type: int Default: 1 Valid Values: [1,...] Importance: medium Update Mode: read-only principal.builder.class
The fully qualified name of a class that implements the KafkaPrincipalBuilder interface, which is used to build the KafkaPrincipal object used during authorization. If no principal builder is defined, the default behavior depends on the security protocol in use. For SSL authentication, the principal will be derived using the rules defined by
ssl.principal.mapping.rulesapplied on the distinguished name from the client certificate if one is provided; otherwise, if client authentication is not required, the principal name will be ANONYMOUS. For SASL authentication, the principal will be derived using the rules defined bysasl.kerberos.principal.to.local.rulesif GSSAPI is in use, and the SASL authentication ID for other mechanisms. For PLAINTEXT, the principal will be ANONYMOUS. Note that custom implementations ofKafkaPrincipalBuilderis required to implementKafkaPrincipalSerdeinterface, otherwise brokers will not be able to forward requests to the controller.Type: class Default: org.apache.kafka.common.security.authenticator.DefaultKafkaPrincipalBuilder Valid Values: Importance: medium Update Mode: per-broker producer.purgatory.purge.interval.requests
The purge interval (in number of requests) of the producer request purgatory
Type: int Default: 1000 Valid Values: Importance: medium Update Mode: read-only queued.max.request.bytes
The number of queued bytes allowed before no more requests are read
Type: long Default: -1 Valid Values: Importance: medium Update Mode: read-only remote.fetch.max.wait.ms
The maximum amount of time the server will wait before answering the remote fetch request
Type: int Default: 500 Valid Values: [1,...] Importance: medium Update Mode: cluster-wide remote.list.offsets.request.timeout.ms
The maximum amount of time the server will wait for the remote list offsets request to complete.
Type: long Default: 30000 (30 seconds) Valid Values: [1,...] Importance: medium Update Mode: cluster-wide remote.log.manager.copier.thread.pool.size
Size of the thread pool used in scheduling tasks to copy segments.
Type: int Default: 10 Valid Values: [1,...] Importance: medium Update Mode: cluster-wide remote.log.manager.copy.max.bytes.per.second
The maximum number of bytes that can be copied from local storage to remote storage per second. This is a global limit for all the partitions that are being copied from local storage to remote storage. The default value is Long.MAX_VALUE, which means there is no limit on the number of bytes that can be copied per second.
Type: long Default: 9223372036854775807 Valid Values: [1,...] Importance: medium Update Mode: cluster-wide remote.log.manager.copy.quota.window.num
The number of samples to retain in memory for remote copy quota management. The default value is 11, which means there are 10 whole windows + 1 current window.
Type: int Default: 11 Valid Values: [1,...] Importance: medium Update Mode: read-only remote.log.manager.copy.quota.window.size.seconds
The time span of each sample for remote copy quota management. The default value is 1 second.
Type: int Default: 1 Valid Values: [1,...] Importance: medium Update Mode: read-only remote.log.manager.expiration.thread.pool.size
Size of the thread pool used in scheduling tasks to clean up the expired remote log segments.
Type: int Default: 10 Valid Values: [1,...] Importance: medium Update Mode: cluster-wide remote.log.manager.fetch.max.bytes.per.second
The maximum number of bytes that can be fetched from remote storage to local storage per second. This is a global limit for all the partitions that are being fetched from remote storage to local storage. The default value is Long.MAX_VALUE, which means there is no limit on the number of bytes that can be fetched per second.
Type: long Default: 9223372036854775807 Valid Values: [1,...] Importance: medium Update Mode: cluster-wide remote.log.manager.fetch.quota.window.num
The number of samples to retain in memory for remote fetch quota management. The default value is 11, which means there are 10 whole windows + 1 current window.
Type: int Default: 11 Valid Values: [1,...] Importance: medium Update Mode: read-only remote.log.manager.fetch.quota.window.size.seconds
The time span of each sample for remote fetch quota management. The default value is 1 second.
Type: int Default: 1 Valid Values: [1,...] Importance: medium Update Mode: read-only remote.log.manager.thread.pool.size
Size of the thread pool used in scheduling follower tasks to read the highest-uploaded remote-offset for follower partitions.
Type: int Default: 2 Valid Values: [1,...] Importance: medium Update Mode: read-only remote.log.metadata.manager.class.name
Fully qualified class name of `RemoteLogMetadataManager` implementation.
Type: string Default: org.apache.kafka.server.log.remote.metadata.storage.TopicBasedRemoteLogMetadataManager Valid Values: non-empty string Importance: medium Update Mode: read-only remote.log.metadata.manager.class.path
Class path of the `RemoteLogMetadataManager` implementation. If specified, the RemoteLogMetadataManager implementation and its dependent libraries will be loaded by a dedicated classloader which searches this class path before the Kafka broker class path. The syntax of this parameter is same as the standard Java class path string.
Type: string Default: null Valid Values: Importance: medium Update Mode: read-only remote.log.metadata.manager.impl.prefix
Prefix used for properties to be passed to RemoteLogMetadataManager implementation. For example this value can be `rlmm.config.`.
Type: string Default: rlmm.config. Valid Values: non-empty string Importance: medium Update Mode: read-only remote.log.metadata.manager.listener.name
Listener name of the local broker to which it should get connected if needed by RemoteLogMetadataManager implementation.
Type: string Default: null Valid Values: non-empty string Importance: medium Update Mode: read-only remote.log.reader.max.pending.tasks
Maximum remote log reader thread pool task queue size. If the task queue is full, fetch requests are served with an error.
Type: int Default: 100 Valid Values: [1,...] Importance: medium Update Mode: read-only remote.log.reader.threads
Size of the thread pool that is allocated for handling remote log reads.
Type: int Default: 10 Valid Values: [1,...] Importance: medium Update Mode: cluster-wide remote.log.storage.manager.class.name
Fully qualified class name of `RemoteStorageManager` implementation.
Type: string Default: null Valid Values: non-empty string Importance: medium Update Mode: read-only remote.log.storage.manager.class.path
Class path of the `RemoteStorageManager` implementation. If specified, the RemoteStorageManager implementation and its dependent libraries will be loaded by a dedicated classloader which searches this class path before the Kafka broker class path. The syntax of this parameter is same as the standard Java class path string.
Type: string Default: null Valid Values: Importance: medium Update Mode: read-only remote.log.storage.manager.impl.prefix
Prefix used for properties to be passed to RemoteStorageManager implementation. For example this value can be `rsm.config.`.
Type: string Default: rsm.config. Valid Values: non-empty string Importance: medium Update Mode: read-only remote.log.storage.system.enable
Whether to enable tiered storage functionality in a broker or not. When it is true broker starts all the services required for the tiered storage functionality.
Type: boolean Default: false Valid Values: Importance: medium Update Mode: read-only replica.fetch.backoff.ms
The amount of time to sleep when fetch partition error occurs.
Type: int Default: 1000 (1 second) Valid Values: [0,...] Importance: medium Update Mode: read-only replica.fetch.max.bytes
The number of bytes of messages to attempt to fetch for each partition. This is not an absolute maximum, if the first record batch in the first non-empty partition of the fetch is larger than this value, the record batch will still be returned to ensure that progress can be made. The maximum record batch size accepted by the broker is defined via
message.max.bytes(broker config) ormax.message.bytes(topic config).Type: int Default: 1048576 (1 mebibyte) Valid Values: [0,...] Importance: medium Update Mode: read-only replica.fetch.response.max.bytes
Maximum bytes expected for the entire fetch response. Records are fetched in batches, and if the first record batch in the first non-empty partition of the fetch is larger than this value, the record batch will still be returned to ensure that progress can be made. As such, this is not an absolute maximum. The maximum record batch size accepted by the broker is defined via
message.max.bytes(broker config) ormax.message.bytes(topic config).Type: int Default: 10485760 (10 mebibytes) Valid Values: [0,...] Importance: medium Update Mode: read-only replica.selector.class
The fully qualified class name that implements ReplicaSelector. This is used by the broker to find the preferred read replica. By default, we use an implementation that returns the leader.
Type: string Default: null Valid Values: Importance: medium Update Mode: read-only sasl.client.callback.handler.class
The fully qualified name of a SASL client callback handler class that implements the AuthenticateCallbackHandler interface.
Type: class Default: null Valid Values: Importance: medium Update Mode: read-only sasl.enabled.mechanisms
The list of SASL mechanisms enabled in the Kafka server. The list may contain any mechanism for which a security provider is available. Only GSSAPI is enabled by default.
Type: list Default: GSSAPI Valid Values: Importance: medium Update Mode: per-broker sasl.jaas.config
JAAS login context parameters for SASL connections in the format used by JAAS configuration files. JAAS configuration file format is described here. The format for the value is:
loginModuleClass controlFlag (optionName=optionValue)*;. For brokers, the config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.jaas.config=com.example.ScramLoginModule required;Type: password Default: null Valid Values: Importance: medium Update Mode: per-broker sasl.kerberos.kinit.cmd
Kerberos kinit command path.
Type: string Default: /usr/bin/kinit Valid Values: Importance: medium Update Mode: per-broker sasl.kerberos.min.time.before.relogin
Login thread sleep time between refresh attempts.
Type: long Default: 60000 Valid Values: Importance: medium Update Mode: per-broker sasl.kerberos.principal.to.local.rules
A list of rules for mapping from principal names to short names (typically operating system usernames). The rules are evaluated in order and the first rule that matches a principal name is used to map it to a short name. Any later rules in the list are ignored. By default, principal names of the form
{username}/{hostname}@{REALM}are mapped to{username}. For more details on the format please see security authorization and acls. Note that this configuration is ignored if an extension ofKafkaPrincipalBuilderis provided by theprincipal.builder.classconfiguration.Type: list Default: DEFAULT Valid Values: Importance: medium Update Mode: per-broker sasl.kerberos.service.name
The Kerberos principal name that Kafka runs as. This can be defined either in Kafka's JAAS config or in Kafka's config.
Type: string Default: null Valid Values: Importance: medium Update Mode: per-broker sasl.kerberos.ticket.renew.jitter
Percentage of random jitter added to the renewal time.
Type: double Default: 0.05 Valid Values: Importance: medium Update Mode: per-broker sasl.kerberos.ticket.renew.window.factor
Login thread will sleep until the specified window factor of time from last refresh to ticket's expiry has been reached, at which time it will try to renew the ticket.
Type: double Default: 0.8 Valid Values: Importance: medium Update Mode: per-broker sasl.login.callback.handler.class
The fully qualified name of a SASL login callback handler class that implements the AuthenticateCallbackHandler interface. For brokers, login callback handler config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.callback.handler.class=com.example.CustomScramLoginCallbackHandler
Type: class Default: null Valid Values: Importance: medium Update Mode: read-only sasl.login.class
The fully qualified name of a class that implements the Login interface. For brokers, login config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.class=com.example.CustomScramLogin
Type: class Default: null Valid Values: Importance: medium Update Mode: read-only sasl.login.refresh.buffer.seconds
The amount of buffer time before credential expiration to maintain when refreshing a credential, in seconds. If a refresh would otherwise occur closer to expiration than the number of buffer seconds then the refresh will be moved up to maintain as much of the buffer time as possible. Legal values are between 0 and 3600 (1 hour); a default value of 300 (5 minutes) is used if no value is specified. This value and sasl.login.refresh.min.period.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 300 Valid Values: Importance: medium Update Mode: per-broker sasl.login.refresh.min.period.seconds
The desired minimum time for the login refresh thread to wait before refreshing a credential, in seconds. Legal values are between 0 and 900 (15 minutes); a default value of 60 (1 minute) is used if no value is specified. This value and sasl.login.refresh.buffer.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 60 Valid Values: Importance: medium Update Mode: per-broker sasl.login.refresh.window.factor
Login refresh thread will sleep until the specified window factor relative to the credential's lifetime has been reached, at which time it will try to refresh the credential. Legal values are between 0.5 (50%) and 1.0 (100%) inclusive; a default value of 0.8 (80%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.8 Valid Values: Importance: medium Update Mode: per-broker sasl.login.refresh.window.jitter
The maximum amount of random jitter relative to the credential's lifetime that is added to the login refresh thread's sleep time. Legal values are between 0 and 0.25 (25%) inclusive; a default value of 0.05 (5%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.05 Valid Values: Importance: medium Update Mode: per-broker sasl.mechanism.inter.broker.protocol
SASL mechanism used for inter-broker communication. Default is GSSAPI.
Type: string Default: GSSAPI Valid Values: Importance: medium Update Mode: per-broker sasl.oauthbearer.jwks.endpoint.url
The OAuth/OIDC provider URL from which the provider's JWKS (JSON Web Key Set) can be retrieved. The URL can be HTTP(S)-based or file-based. If the URL is HTTP(S)-based, the JWKS data will be retrieved from the OAuth/OIDC provider via the configured URL on broker startup. All then-current keys will be cached on the broker for incoming requests. If an authentication request is received for a JWT that includes a "kid" header claim value that isn't yet in the cache, the JWKS endpoint will be queried again on demand. However, the broker polls the URL every sasl.oauthbearer.jwks.endpoint.refresh.ms milliseconds to refresh the cache with any forthcoming keys before any JWT requests that include them are received. If the URL is file-based, the broker will load the JWKS file from a configured location on startup. In the event that the JWT includes a "kid" header value that isn't in the JWKS file, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: medium Update Mode: read-only sasl.oauthbearer.token.endpoint.url
The URL for the OAuth/OIDC identity provider. If the URL is HTTP(S)-based, it is the issuer's token endpoint URL to which requests will be made to login based on the configuration in sasl.jaas.config. If the URL is file-based, it specifies a file containing an access token (in JWT serialized form) issued by the OAuth/OIDC identity provider to use for authorization.
Type: string Default: null Valid Values: Importance: medium Update Mode: read-only sasl.server.callback.handler.class
The fully qualified name of a SASL server callback handler class that implements the AuthenticateCallbackHandler interface. Server callback handlers must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.plain.sasl.server.callback.handler.class=com.example.CustomPlainCallbackHandler.
Type: class Default: null Valid Values: Importance: medium Update Mode: read-only sasl.server.max.receive.size
The maximum receive size allowed before and during initial SASL authentication. Default receive size is 512KB. GSSAPI limits requests to 64K, but we allow upto 512KB by default for custom SASL mechanisms. In practice, PLAIN, SCRAM and OAUTH mechanisms can use much smaller limits.
Type: int Default: 524288 Valid Values: Importance: medium Update Mode: read-only security.inter.broker.protocol
Security protocol used to communicate between brokers. It is an error to set this and inter.broker.listener.name properties at the same time.
Type: string Default: PLAINTEXT Valid Values: [PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL] Importance: medium Update Mode: read-only share.coordinator.append.linger.ms
The duration in milliseconds that the share coordinator will wait for writes to accumulate before flushing them to disk.
Type: int Default: 10 Valid Values: [0,...] Importance: medium Update Mode: read-only share.coordinator.snapshot.update.records.per.snapshot
The number of update records the share coordinator writes between snapshot records.
Type: int Default: 500 Valid Values: [0,...] Importance: medium Update Mode: read-only share.coordinator.threads
The number of threads used by the share coordinator.
Type: int Default: 1 Valid Values: [1,...] Importance: medium Update Mode: read-only share.fetch.purgatory.purge.interval.requests
The purge interval (in number of requests) of the share fetch request purgatory
Type: int Default: 1000 Valid Values: Importance: medium Update Mode: read-only socket.connection.setup.timeout.max.ms
The maximum amount of time the client will wait for the socket connection to be established. The connection setup timeout will increase exponentially for each consecutive connection failure up to this maximum. To avoid connection storms, a randomization factor of 0.2 will be applied to the timeout resulting in a random range between 20% below and 20% above the computed value.
Type: long Default: 30000 (30 seconds) Valid Values: Importance: medium Update Mode: read-only socket.connection.setup.timeout.ms
The amount of time the client will wait for the socket connection to be established. If the connection is not built before the timeout elapses, clients will close the socket channel. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the
socket.connection.setup.timeout.max.msvalue.Type: long Default: 10000 (10 seconds) Valid Values: Importance: medium Update Mode: read-only socket.listen.backlog.size
The maximum number of pending connections on the socket. In Linux, you may also need to configure
somaxconnandtcp_max_syn_backlogkernel parameters accordingly to make the configuration takes effect.Type: int Default: 50 Valid Values: [1,...] Importance: medium Update Mode: read-only ssl.cipher.suites
A list of cipher suites. This is a named combination of authentication, encryption, MAC and key exchange algorithm used to negotiate the security settings for a network connection using TLS or SSL network protocol. By default all the available cipher suites are supported.
Type: list Default: "" Valid Values: Importance: medium Update Mode: per-broker ssl.client.auth
Configures kafka broker to request client authentication. The following settings are common:
ssl.client.auth=requiredIf set to required client authentication is required.ssl.client.auth=requestedThis means client authentication is optional. unlike required, if this option is set client can choose not to provide authentication information about itselfssl.client.auth=noneThis means client authentication is not needed.
Type: string Default: none Valid Values: [required, requested, none] Importance: medium Update Mode: per-broker ssl.enabled.protocols
The list of protocols enabled for SSL connections. The default is 'TLSv1.2,TLSv1.3'. This means that clients and servers will prefer TLSv1.3 if both support it and fallback to TLSv1.2 otherwise (assuming both support at least TLSv1.2). This default should be fine for most use cases. Also see the config documentation for `ssl.protocol` to understand how it can impact the TLS version negotiation behavior.
Type: list Default: TLSv1.2,TLSv1.3 Valid Values: Importance: medium Update Mode: per-broker ssl.key.password
The password of the private key in the key store file or the PEM key specified in 'ssl.keystore.key'.
Type: password Default: null Valid Values: Importance: medium Update Mode: per-broker ssl.keymanager.algorithm
The algorithm used by key manager factory for SSL connections. Default value is the key manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: SunX509 Valid Values: Importance: medium Update Mode: per-broker ssl.keystore.certificate.chain
Certificate chain in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with a list of X.509 certificates
Type: password Default: null Valid Values: Importance: medium Update Mode: per-broker ssl.keystore.key
Private key in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with PKCS#8 keys. If the key is encrypted, key password must be specified using 'ssl.key.password'
Type: password Default: null Valid Values: Importance: medium Update Mode: per-broker ssl.keystore.location
The location of the key store file. This is optional for client and can be used for two-way authentication for client.
Type: string Default: null Valid Values: Importance: medium Update Mode: per-broker ssl.keystore.password
The store password for the key store file. This is optional for client and only needed if 'ssl.keystore.location' is configured. Key store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: medium Update Mode: per-broker ssl.keystore.type
The file format of the key store file. This is optional for client. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium Update Mode: per-broker ssl.protocol
The SSL protocol used to generate the SSLContext. The default is 'TLSv1.3', which should be fine for most use cases. A typical alternative to the default is 'TLSv1.2'. Allowed values for this config are dependent on the JVM. Clients using the defaults for this config and 'ssl.enabled.protocols' will downgrade to 'TLSv1.2' if the server does not support 'TLSv1.3'. If this config is set to 'TLSv1.2', however, clients will not use 'TLSv1.3' even if it is one of the values in `ssl.enabled.protocols` and the server only supports 'TLSv1.3'.
Type: string Default: TLSv1.3 Valid Values: Importance: medium Update Mode: per-broker ssl.provider
The name of the security provider used for SSL connections. Default value is the default security provider of the JVM.
Type: string Default: null Valid Values: Importance: medium Update Mode: per-broker ssl.trustmanager.algorithm
The algorithm used by trust manager factory for SSL connections. Default value is the trust manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: PKIX Valid Values: Importance: medium Update Mode: per-broker ssl.truststore.certificates
Trusted certificates in the format specified by 'ssl.truststore.type'. Default SSL engine factory supports only PEM format with X.509 certificates.
Type: password Default: null Valid Values: Importance: medium Update Mode: per-broker ssl.truststore.location
The location of the trust store file.
Type: string Default: null Valid Values: Importance: medium Update Mode: per-broker ssl.truststore.password
The password for the trust store file. If a password is not set, trust store file configured will still be used, but integrity checking is disabled. Trust store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: medium Update Mode: per-broker ssl.truststore.type
The file format of the trust store file. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium Update Mode: per-broker alter.config.policy.class.name
The alter configs policy class that should be used for validation. The class should implement the
org.apache.kafka.server.policy.AlterConfigPolicyinterface.Note: This policy runs on the controller instead of the broker.
Type: class Default: null Valid Values: Importance: low Update Mode: read-only alter.log.dirs.replication.quota.window.num
The number of samples to retain in memory for alter log dirs replication quotas
Type: int Default: 11 Valid Values: [1,...] Importance: low Update Mode: read-only alter.log.dirs.replication.quota.window.size.seconds
The time span of each sample for alter log dirs replication quotas
Type: int Default: 1 Valid Values: [1,...] Importance: low Update Mode: read-only authorizer.class.name
The fully qualified name of a class that implements
org.apache.kafka.server.authorizer.Authorizerinterface, which is used by the broker for authorization.Type: string Default: "" Valid Values: non-null string Importance: low Update Mode: read-only client.quota.callback.class
The fully qualified name of a class that implements the ClientQuotaCallback interface, which is used to determine quota limits applied to client requests. For any given request, the most specific quota that matches the user principal of the session and the client-id of the request is applied.
Type: class Default: null Valid Values: Importance: low Update Mode: read-only connection.failed.authentication.delay.ms
Connection close delay on failed authentication: this is the time (in milliseconds) by which connection close will be delayed on authentication failure. This must be configured to be less than connections.max.idle.ms to prevent connection timeout.
Type: int Default: 100 Valid Values: [0,...] Importance: low Update Mode: read-only controller.quorum.retry.backoff.ms
The amount of time to wait before attempting to retry a failed request to a given topic partition. This avoids repeatedly sending requests in a tight loop under some failure scenarios. This value is the initial backoff value and will increase exponentially for each failed request, up to the
retry.backoff.max.msvalue.Type: int Default: 20 Valid Values: Importance: low Update Mode: read-only controller.quota.window.num
The number of samples to retain in memory for controller mutation quotas
Type: int Default: 11 Valid Values: [1,...] Importance: low Update Mode: read-only controller.quota.window.size.seconds
The time span of each sample for controller mutations quotas
Type: int Default: 1 Valid Values: [1,...] Importance: low Update Mode: read-only create.topic.policy.class.name
The create topic policy class that should be used for validation. The class should implement the
org.apache.kafka.server.policy.CreateTopicPolicyinterface.Note: This policy runs on the controller instead of the broker.
Type: class Default: null Valid Values: Importance: low Update Mode: read-only delegation.token.expiry.check.interval.ms
Scan interval to remove expired delegation tokens.
Type: long Default: 3600000 (1 hour) Valid Values: [1,...] Importance: low Update Mode: read-only kafka.metrics.polling.interval.secs
The metrics polling interval (in seconds) which can be used in kafka.metrics.reporters implementations.
Type: int Default: 10 Valid Values: [1,...] Importance: low Update Mode: read-only kafka.metrics.reporters
A list of classes to use as Yammer metrics custom reporters. The reporters should implement
kafka.metrics.KafkaMetricsReportertrait. If a client wants to expose JMX operations on a custom reporter, the custom reporter needs to additionally implement an MBean trait that extendskafka.metrics.KafkaMetricsReporterMBeantrait so that the registered MBean is compliant with the standard MBean convention.Type: list Default: "" Valid Values: Importance: low Update Mode: read-only listener.security.protocol.map
Map between listener names and security protocols. This must be defined for the same security protocol to be usable in more than one port or IP. For example, internal and external traffic can be separated even if SSL is required for both. Concretely, the user could define listeners with names INTERNAL and EXTERNAL and this property as:
INTERNAL:SSL,EXTERNAL:SSL. As shown, key and value are separated by a colon and map entries are separated by commas. Each listener name should only appear once in the map. Different security (SSL and SASL) settings can be configured for each listener by adding a normalised prefix (the listener name is lowercased) to the config name. For example, to set a different keystore for the INTERNAL listener, a config with namelistener.name.internal.ssl.keystore.locationwould be set. If the config for the listener name is not set, the config will fallback to the generic config (i.e.ssl.keystore.location). Note that in KRaft a default mapping from the listener names defined bycontroller.listener.namesto PLAINTEXT is assumed if no explicit mapping is provided and no other security protocol is in use.Type: string Default: SASL_SSL:SASL_SSL,PLAINTEXT:PLAINTEXT,SSL:SSL,SASL_PLAINTEXT:SASL_PLAINTEXT Valid Values: Importance: low Update Mode: per-broker log.dir.failure.timeout.ms
If the broker is unable to successfully communicate to the controller that some log directory has failed for longer than this time, the broker will fail and shut down.
Type: long Default: 30000 (30 seconds) Valid Values: [1,...] Importance: low Update Mode: read-only metadata.max.idle.interval.ms
This configuration controls how often the active controller should write no-op records to the metadata partition. If the value is 0, no-op records are not appended to the metadata partition. The default value is 500
Type: int Default: 500 Valid Values: [0,...] Importance: low Update Mode: read-only metric.reporters
A list of classes to use as metrics reporters. Implementing the
org.apache.kafka.common.metrics.MetricsReporterinterface allows plugging in classes that will be notified of new metric creation.Type: list Default: org.apache.kafka.common.metrics.JmxReporter Valid Values: Importance: low Update Mode: cluster-wide metrics.num.samples
The number of samples maintained to compute metrics.
Type: int Default: 2 Valid Values: [1,...] Importance: low Update Mode: read-only metrics.recording.level
The highest recording level for metrics. It has three levels for recording metrics - info, debug, and trace.
INFO level records only essential metrics necessary for monitoring system performance and health. It collects vital data without gathering too much detail, making it suitable for production environments where minimal overhead is desired.
DEBUG level records most metrics, providing more detailed information about the system's operation. It's useful for development and testing environments where you need deeper insights to debug and fine-tune the application.
TRACE level records all possible metrics, capturing every detail about the system's performance and operation. It's best for controlled environments where in-depth analysis is required, though it can introduce significant overhead.Type: string Default: INFO Valid Values: Importance: low Update Mode: read-only metrics.sample.window.ms
The window of time a metrics sample is computed over.
Type: long Default: 30000 (30 seconds) Valid Values: [1,...] Importance: low Update Mode: read-only producer.id.expiration.ms
The time in ms that a topic partition leader will wait before expiring producer IDs. Producer IDs will not expire while a transaction associated to them is still ongoing. Note that producer IDs may expire sooner if the last write from the producer ID is deleted due to the topic's retention settings. Setting this value the same or higher than
delivery.timeout.mscan help prevent expiration during retries and protect against message duplication, but the default should be reasonable for most use cases.Type: int Default: 86400000 (1 day) Valid Values: [1,...] Importance: low Update Mode: cluster-wide quota.window.num
The number of samples to retain in memory for client quotas
Type: int Default: 11 Valid Values: [1,...] Importance: low Update Mode: read-only quota.window.size.seconds
The time span of each sample for client quotas
Type: int Default: 1 Valid Values: [1,...] Importance: low Update Mode: read-only remote.log.index.file.cache.total.size.bytes
The total size of the space allocated to store index files fetched from remote storage in the local storage.
Type: long Default: 1073741824 (1 gibibyte) Valid Values: [1,...] Importance: low Update Mode: cluster-wide remote.log.manager.task.interval.ms
Interval at which remote log manager runs the scheduled tasks like copy segments, and clean up remote log segments.
Type: long Default: 30000 (30 seconds) Valid Values: [1,...] Importance: low Update Mode: read-only remote.log.metadata.custom.metadata.max.bytes
The maximum size of custom metadata in bytes that the broker should accept from a remote storage plugin. If custom metadata exceeds this limit, the updated segment metadata will not be stored, the copied data will be attempted to delete, and the remote copying task for this topic-partition will stop with an error.
Type: int Default: 128 Valid Values: [0,...] Importance: low Update Mode: read-only replication.quota.window.num
The number of samples to retain in memory for replication quotas
Type: int Default: 11 Valid Values: [1,...] Importance: low Update Mode: read-only replication.quota.window.size.seconds
The time span of each sample for replication quotas
Type: int Default: 1 Valid Values: [1,...] Importance: low Update Mode: read-only sasl.login.connect.timeout.ms
The (optional) value in milliseconds for the external authentication provider connection timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low Update Mode: read-only sasl.login.read.timeout.ms
The (optional) value in milliseconds for the external authentication provider read timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low Update Mode: read-only sasl.login.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low Update Mode: read-only sasl.login.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 100 Valid Values: Importance: low Update Mode: read-only sasl.oauthbearer.clock.skew.seconds
The (optional) value in seconds to allow for differences between the time of the OAuth/OIDC identity provider and the broker.
Type: int Default: 30 Valid Values: Importance: low Update Mode: read-only sasl.oauthbearer.expected.audience
The (optional) comma-delimited setting for the broker to use to verify that the JWT was issued for one of the expected audiences. The JWT will be inspected for the standard OAuth "aud" claim and if this value is set, the broker will match the value from JWT's "aud" claim to see if there is an exact match. If there is no match, the broker will reject the JWT and authentication will fail.
Type: list Default: null Valid Values: Importance: low Update Mode: read-only sasl.oauthbearer.expected.issuer
The (optional) setting for the broker to use to verify that the JWT was created by the expected issuer. The JWT will be inspected for the standard OAuth "iss" claim and if this value is set, the broker will match it exactly against what is in the JWT's "iss" claim. If there is no match, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: low Update Mode: read-only sasl.oauthbearer.jwks.endpoint.refresh.ms
The (optional) value in milliseconds for the broker to wait between refreshing its JWKS (JSON Web Key Set) cache that contains the keys to verify the signature of the JWT.
Type: long Default: 3600000 (1 hour) Valid Values: Importance: low Update Mode: read-only sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between attempts to retrieve the JWKS (JSON Web Key Set) from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low Update Mode: read-only sasl.oauthbearer.jwks.endpoint.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between JWKS (JSON Web Key Set) retrieval attempts from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 100 Valid Values: Importance: low Update Mode: read-only sasl.oauthbearer.scope.claim.name
The OAuth claim for the scope is often named "scope", but this (optional) setting can provide a different name to use for the scope included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: scope Valid Values: Importance: low Update Mode: read-only sasl.oauthbearer.sub.claim.name
The OAuth claim for the subject is often named "sub", but this (optional) setting can provide a different name to use for the subject included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: sub Valid Values: Importance: low Update Mode: read-only security.providers
A list of configurable creator classes each returning a provider implementing security algorithms. These classes should implement the
org.apache.kafka.common.security.auth.SecurityProviderCreatorinterface.Type: string Default: null Valid Values: Importance: low Update Mode: read-only ssl.allow.dn.changes
Indicates whether changes to the certificate distinguished name should be allowed during a dynamic reconfiguration of certificates or not.
Type: boolean Default: false Valid Values: Importance: low Update Mode: read-only ssl.allow.san.changes
Indicates whether changes to the certificate subject alternative names should be allowed during a dynamic reconfiguration of certificates or not.
Type: boolean Default: false Valid Values: Importance: low Update Mode: read-only ssl.endpoint.identification.algorithm
The endpoint identification algorithm to validate server hostname using server certificate.
Type: string Default: https Valid Values: Importance: low Update Mode: per-broker ssl.engine.factory.class
The class of type org.apache.kafka.common.security.auth.SslEngineFactory to provide SSLEngine objects. Default value is org.apache.kafka.common.security.ssl.DefaultSslEngineFactory. Alternatively, setting this to org.apache.kafka.common.security.ssl.CommonNameLoggingSslEngineFactory will log the common name of expired SSL certificates used by clients to authenticate at any of the brokers with log level INFO. Note that this will cause a tiny delay during establishment of new connections from mTLS clients to brokers due to the extra code for examining the certificate chain provided by the client. Note further that the implementation uses a custom truststore based on the standard Java truststore and thus might be considered a security risk due to not being as mature as the standard one.
Type: class Default: null Valid Values: Importance: low Update Mode: per-broker ssl.principal.mapping.rules
A list of rules for mapping from distinguished name from the client certificate to short name. The rules are evaluated in order and the first rule that matches a principal name is used to map it to a short name. Any later rules in the list are ignored. By default, distinguished name of the X.500 certificate will be the principal. For more details on the format please see security authorization and acls. Note that this configuration is ignored if an extension of KafkaPrincipalBuilder is provided by the
principal.builder.classconfiguration.Type: string Default: DEFAULT Valid Values: Importance: low Update Mode: read-only ssl.secure.random.implementation
The SecureRandom PRNG implementation to use for SSL cryptography operations.
Type: string Default: null Valid Values: Importance: low Update Mode: per-broker telemetry.max.bytes
The maximum size (after compression if compression is used) of telemetry metrics pushed from a client to the broker. The default value is 1048576 (1 MB).
Type: int Default: 1048576 (1 mebibyte) Valid Values: [1,...] Importance: low Update Mode: read-only transaction.abort.timed.out.transaction.cleanup.interval.ms
The interval at which to rollback transactions that have timed out
Type: int Default: 10000 (10 seconds) Valid Values: [1,...] Importance: low Update Mode: read-only transaction.partition.verification.enable
Enable verification that checks that the partition has been added to the transaction before writing transactional records to the partition
Type: boolean Default: true Valid Values: Importance: low Update Mode: cluster-wide transaction.remove.expired.transaction.cleanup.interval.ms
The interval at which to remove transactions that have expired due to
transactional.id.expiration.mspassingType: int Default: 3600000 (1 hour) Valid Values: [1,...] Importance: low Update Mode: read-only
More details about broker configuration can be found in the scala class kafka.server.KafkaConfig.
Updating Broker Configs
From Kafka version 1.1 onwards, some of the broker configs can be updated without restarting the broker. See the Dynamic Update Mode column in Broker Configs for the update mode of each broker config.
read-only: Requires a broker restart for updateper-broker: May be updated dynamically for each brokercluster-wide: May be updated dynamically as a cluster-wide default. May also be updated as a per-broker value for testing.
To alter the current broker configs for broker id 0 (for example, the number of log cleaner threads):
$ bin/kafka-configs.sh --bootstrap-server localhost:9092 --entity-type brokers --entity-name 0 --alter --add-config log.cleaner.threads=2
To describe the current dynamic broker configs for broker id 0:
$ bin/kafka-configs.sh --bootstrap-server localhost:9092 --entity-type brokers --entity-name 0 --describe
To delete a config override and revert to the statically configured or default value for broker id 0 (for example, the number of log cleaner threads):
$ bin/kafka-configs.sh --bootstrap-server localhost:9092 --entity-type brokers --entity-name 0 --alter --delete-config log.cleaner.threads
Some configs may be configured as a cluster-wide default to maintain consistent values across the whole cluster. All brokers in the cluster will process the cluster default update. For example, to update log cleaner threads on all brokers:
$ bin/kafka-configs.sh --bootstrap-server localhost:9092 --entity-type brokers --entity-default --alter --add-config log.cleaner.threads=2
To describe the currently configured dynamic cluster-wide default configs:
$ bin/kafka-configs.sh --bootstrap-server localhost:9092 --entity-type brokers --entity-default --describe
All configs that are configurable at cluster level may also be configured at per-broker level (e.g. for testing). If a config value is defined at different levels, the following order of precedence is used:
- Dynamic per-broker config stored in the metadata log
- Dynamic cluster-wide default config stored in the metadata log
- Static broker config from
server.properties - Kafka default, see broker configs
Updating SSL Keystore of an Existing Listener
Brokers may be configured with SSL keystores with short validity periods to reduce the risk of compromised certificates. Keystores may be updated dynamically without restarting the broker. The config name must be prefixed with the listener prefix listener.name.{listenerName}. so that only the keystore config of a specific listener is updated. The following configs may be updated in a single alter request at per-broker level:
ssl.keystore.typessl.keystore.locationssl.keystore.passwordssl.key.password
If the listener is the inter-broker listener, the update is allowed only if the new keystore is trusted by the truststore configured for that listener. For other listeners, no trust validation is performed on the keystore by the broker. Certificates must be signed by the same certificate authority that signed the old certificate to avoid any client authentication failures.
Updating SSL Truststore of an Existing Listener
Broker truststores may be updated dynamically without restarting the broker to add or remove certificates. Updated truststore will be used to authenticate new client connections. The config name must be prefixed with the listener prefix listener.name.{listenerName}. so that only the truststore config of a specific listener is updated. The following configs may be updated in a single alter request at per-broker level:
ssl.truststore.typessl.truststore.locationssl.truststore.password
If the listener is the inter-broker listener, the update is allowed only if the existing keystore for that listener is trusted by the new truststore. For other listeners, no trust validation is performed by the broker before the update. Removal of CA certificates used to sign client certificates from the new truststore can lead to client authentication failures.
Updating Default Topic Configuration
Default topic configuration options used by brokers may be updated without broker restart. The configs are applied to topics without a topic config override for the equivalent per-topic config. One or more of these configs may be overridden at cluster-default level used by all brokers.
log.segment.byteslog.roll.mslog.roll.hourslog.roll.jitter.mslog.roll.jitter.hourslog.index.size.max.byteslog.flush.interval.messageslog.flush.interval.mslog.retention.byteslog.retention.mslog.retention.minuteslog.retention.hourslog.index.interval.byteslog.cleaner.delete.retention.mslog.cleaner.min.compaction.lag.mslog.cleaner.max.compaction.lag.mslog.cleaner.min.cleanable.ratiolog.cleanup.policylog.segment.delete.delay.msunclean.leader.election.enablemin.insync.replicasmax.message.bytescompression.typelog.preallocatelog.message.timestamp.type
Updating Log Cleaner Configs
Log cleaner configs may be updated dynamically at cluster-default level used by all brokers. The changes take effect on the next iteration of log cleaning. One or more of these configs may be updated:
log.cleaner.threadslog.cleaner.io.max.bytes.per.secondlog.cleaner.dedupe.buffer.sizelog.cleaner.io.buffer.sizelog.cleaner.io.buffer.load.factorlog.cleaner.backoff.ms
Updating Thread Configs
The size of various thread pools used by the broker may be updated dynamically at cluster-default level used by all brokers. Updates are restricted to the range currentSize / 2 to currentSize * 2 to ensure that config updates are handled gracefully.
num.network.threadsnum.io.threadsnum.replica.fetchersnum.recovery.threads.per.data.dirlog.cleaner.threadsbackground.threadsremote.log.reader.threadsremote.log.manager.copier.thread.pool.sizeremote.log.manager.expiration.thread.pool.size
Updating ConnectionQuota Configs
The maximum number of connections allowed for a given IP/host by the broker may be updated dynamically at cluster-default level used by all brokers. The changes will apply for new connection creations and the existing connections count will be taken into account by the new limits.
max.connections.per.ipmax.connections.per.ip.overrides
Adding and Removing Listeners
Listeners may be added or removed dynamically. When a new listener is added, security configs of the listener must be provided as listener configs with the listener prefix listener.name.{listenerName}.. If the new listener uses SASL, the JAAS configuration of the listener must be provided using the JAAS configuration property sasl.jaas.config with the listener and mechanism prefix. See JAAS configuration for Kafka brokers for details.
In Kafka version 1.1.x, the listener used by the inter-broker listener may not be updated dynamically. To update the inter-broker listener to a new listener, the new listener may be added on all brokers without restarting the broker. A rolling restart is then required to update inter.broker.listener.name.
In addition to all the security configs of new listeners, the following configs may be updated dynamically at per-broker level:
listenersadvertised.listenerslistener.security.protocol.map
Inter-broker listener must be configured using the static broker configuration inter.broker.listener.name or security.inter.broker.protocol.
Topic-Level Configs
Configurations pertinent to topics have both a server default as well an optional per-topic override. If no per-topic configuration is given the server default is used. The override can be set at topic creation time by giving one or more --config options. This example creates a topic named my-topic with a custom max message size and flush rate:
$ bin/kafka-topics.sh --bootstrap-server localhost:9092 --create --topic my-topic --partitions 1 \
--replication-factor 1 --config max.message.bytes=64000 --config flush.messages=1
Overrides can also be changed or set later using the alter configs command. This example updates the max message size for my-topic :
$ bin/kafka-configs.sh --bootstrap-server localhost:9092 --entity-type topics --entity-name my-topic
--alter --add-config max.message.bytes=128000
To check overrides set on the topic you can do
$ bin/kafka-configs.sh --bootstrap-server localhost:9092 --entity-type topics --entity-name my-topic --describe
To remove an override you can do
$ bin/kafka-configs.sh --bootstrap-server localhost:9092 --entity-type topics --entity-name my-topic
--alter --delete-config max.message.bytes
The following are the topic-level configurations. The server’s default configuration for this property is given under the Server Default Property heading. A given server default config value only applies to a topic if it does not have an explicit topic config override.
cleanup.policy
This config designates the retention policy to use on log segments. The "delete" policy (which is the default) will discard old segments when their retention time or size limit has been reached. The "compact" policy will enable log compaction, which retains the latest value for each key. It is also possible to specify both policies in a comma-separated list (e.g. "delete,compact"). In this case, old segments will be discarded per the retention time and size configuration, while retained segments will be compacted.
Type: list Default: delete Valid Values: [compact, delete] Server Default Property: log.cleanup.policy Importance: medium compression.gzip.level
The compression level to use if compression.type is set to
gzip.Type: int Default: -1 Valid Values: [1,...,9] or -1 Server Default Property: compression.gzip.level Importance: medium compression.lz4.level
The compression level to use if compression.type is set to
lz4.Type: int Default: 9 Valid Values: [1,...,17] Server Default Property: compression.lz4.level Importance: medium compression.type
Specify the final compression type for a given topic. This configuration accepts the standard compression codecs ('gzip', 'snappy', 'lz4', 'zstd'). It additionally accepts 'uncompressed' which is equivalent to no compression; and 'producer' which means retain the original compression codec set by the producer.
Type: string Default: producer Valid Values: [uncompressed, zstd, lz4, snappy, gzip, producer] Server Default Property: compression.type Importance: medium compression.zstd.level
The compression level to use if compression.type is set to
zstd.Type: int Default: 3 Valid Values: [-131072,...,22] Server Default Property: compression.zstd.level Importance: medium delete.retention.ms
The amount of time to retain delete tombstone markers for log compacted topics. This setting also gives a bound on the time in which a consumer must complete a read if they begin from offset 0 to ensure that they get a valid snapshot of the final stage (otherwise delete tombstones may be collected before they complete their scan).
Type: long Default: 86400000 (1 day) Valid Values: [0,...] Server Default Property: log.cleaner.delete.retention.ms Importance: medium file.delete.delay.ms
The time to wait before deleting a file from the filesystem
Type: long Default: 60000 (1 minute) Valid Values: [0,...] Server Default Property: log.segment.delete.delay.ms Importance: medium flush.messages
This setting allows specifying an interval at which we will force an fsync of data written to the log. For example if this was set to 1 we would fsync after every message; if it were 5 we would fsync after every five messages. In general we recommend you not set this and use replication for durability and allow the operating system's background flush capabilities as it is more efficient. This setting can be overridden on a per-topic basis (see the per-topic configuration section).
Type: long Default: 9223372036854775807 Valid Values: [1,...] Server Default Property: log.flush.interval.messages Importance: medium flush.ms
This setting allows specifying a time interval at which we will force an fsync of data written to the log. For example if this was set to 1000 we would fsync after 1000 ms had passed. In general we recommend you not set this and use replication for durability and allow the operating system's background flush capabilities as it is more efficient.
Type: long Default: 9223372036854775807 Valid Values: [0,...] Server Default Property: log.flush.interval.ms Importance: medium follower.replication.throttled.replicas
A list of replicas for which log replication should be throttled on the follower side. The list should describe a set of replicas in the form [PartitionId]:[BrokerId],[PartitionId]:[BrokerId]:... or alternatively the wildcard '*' can be used to throttle all replicas for this topic.
Type: list Default: "" Valid Values: [partitionId]:[brokerId],[partitionId]:[brokerId],... Server Default Property: null Importance: medium index.interval.bytes
This setting controls how frequently Kafka adds an index entry to its offset index. The default setting ensures that we index a message roughly every 4096 bytes. More indexing allows reads to jump closer to the exact position in the log but makes the index larger. You probably don't need to change this.
Type: int Default: 4096 (4 kibibytes) Valid Values: [0,...] Server Default Property: log.index.interval.bytes Importance: medium leader.replication.throttled.replicas
A list of replicas for which log replication should be throttled on the leader side. The list should describe a set of replicas in the form [PartitionId]:[BrokerId],[PartitionId]:[BrokerId]:... or alternatively the wildcard '*' can be used to throttle all replicas for this topic.
Type: list Default: "" Valid Values: [partitionId]:[brokerId],[partitionId]:[brokerId],... Server Default Property: null Importance: medium local.retention.bytes
The maximum size of local log segments that can grow for a partition before it deletes the old segments. Default value is -2, it represents `retention.bytes` value to be used. The effective value should always be less than or equal to `retention.bytes` value.
Type: long Default: -2 Valid Values: [-2,...] Server Default Property: log.local.retention.bytes Importance: medium local.retention.ms
The number of milliseconds to keep the local log segment before it gets deleted. Default value is -2, it represents `retention.ms` value is to be used. The effective value should always be less than or equal to `retention.ms` value.
Type: long Default: -2 Valid Values: [-2,...] Server Default Property: log.local.retention.ms Importance: medium max.compaction.lag.ms
The maximum time a message will remain ineligible for compaction in the log. Only applicable for logs that are being compacted.
Type: long Default: 9223372036854775807 Valid Values: [1,...] Server Default Property: log.cleaner.max.compaction.lag.ms Importance: medium max.message.bytes
The largest record batch size allowed by Kafka (after compression if compression is enabled). If this is increased and there are consumers older than 0.10.2, the consumers' fetch size must also be increased so that they can fetch record batches this large. In the latest message format version, records are always grouped into batches for efficiency. In previous message format versions, uncompressed records are not grouped into batches and this limit only applies to a single record in that case.
Type: int Default: 1048588 Valid Values: [0,...] Server Default Property: message.max.bytes Importance: medium message.timestamp.after.max.ms
This configuration sets the allowable timestamp difference between the message timestamp and the broker's timestamp. The message timestamp can be later than or equal to the broker's timestamp, with the maximum allowable difference determined by the value set in this configuration. If message.timestamp.type=CreateTime, the message will be rejected if the difference in timestamps exceeds this specified threshold. This configuration is ignored if message.timestamp.type=LogAppendTime.
Type: long Default: 3600000 (1 hour) Valid Values: [0,...] Server Default Property: log.message.timestamp.after.max.ms Importance: medium message.timestamp.before.max.ms
This configuration sets the allowable timestamp difference between the broker's timestamp and the message timestamp. The message timestamp can be earlier than or equal to the broker's timestamp, with the maximum allowable difference determined by the value set in this configuration. If message.timestamp.type=CreateTime, the message will be rejected if the difference in timestamps exceeds this specified threshold. This configuration is ignored if message.timestamp.type=LogAppendTime.
Type: long Default: 9223372036854775807 Valid Values: [0,...] Server Default Property: log.message.timestamp.before.max.ms Importance: medium message.timestamp.type
Define whether the timestamp in the message is message create time or log append time.
Type: string Default: CreateTime Valid Values: [CreateTime, LogAppendTime] Server Default Property: log.message.timestamp.type Importance: medium min.cleanable.dirty.ratio
This configuration controls how frequently the log compactor will attempt to clean the log (assuming log compaction is enabled). By default we will avoid cleaning a log where more than 50% of the log has been compacted. This ratio bounds the maximum space wasted in the log by duplicates (at 50% at most 50% of the log could be duplicates). A higher ratio will mean fewer, more efficient cleanings but will mean more wasted space in the log. If the max.compaction.lag.ms or the min.compaction.lag.ms configurations are also specified, then the log compactor considers the log to be eligible for compaction as soon as either: (i) the dirty ratio threshold has been met and the log has had dirty (uncompacted) records for at least the min.compaction.lag.ms duration, or (ii) if the log has had dirty (uncompacted) records for at most the max.compaction.lag.ms period.
Type: double Default: 0.5 Valid Values: [0,...,1] Server Default Property: log.cleaner.min.cleanable.ratio Importance: medium min.compaction.lag.ms
The minimum time a message will remain uncompacted in the log. Only applicable for logs that are being compacted.
Type: long Default: 0 Valid Values: [0,...] Server Default Property: log.cleaner.min.compaction.lag.ms Importance: medium min.insync.replicas
When a producer sets acks to "all" (or "-1"), this configuration specifies the minimum number of replicas that must acknowledge a write for the write to be considered successful. If this minimum cannot be met, then the producer will raise an exception (either
NotEnoughReplicasorNotEnoughReplicasAfterAppend).
Regardless of theackssetting, the messages will not be visible to the consumers until they are replicated to all in-sync replicas and themin.insync.replicascondition is met.
When used together,min.insync.replicasandacksallow you to enforce greater durability guarantees. A typical scenario would be to create a topic with a replication factor of 3, setmin.insync.replicasto 2, and produce withacksof "all". This will ensure that a majority of replicas must persist a write before it's considered successful by the producer and it's visible to consumers.Type: int Default: 1 Valid Values: [1,...] Server Default Property: min.insync.replicas Importance: medium preallocate
True if we should preallocate the file on disk when creating a new log segment.
Type: boolean Default: false Valid Values: Server Default Property: log.preallocate Importance: medium remote.log.copy.disable
Determines whether tiered data for a topic should become read only, and no more data uploading on a topic. Once this config is set to true, the local retention configuration (i.e. local.retention.ms/bytes) becomes irrelevant, and all data expiration follows the topic-wide retention configuration(i.e. retention.ms/bytes).
Type: boolean Default: false Valid Values: Server Default Property: null Importance: medium remote.log.delete.on.disable
Determines whether tiered data for a topic should be deleted after tiered storage is disabled on a topic. This configuration should be enabled when trying to set `remote.storage.enable` from true to false
Type: boolean Default: false Valid Values: Server Default Property: null Importance: medium remote.storage.enable
To enable tiered storage for a topic, set this configuration as true. You can not disable this config once it is enabled. It will be provided in future versions.
Type: boolean Default: false Valid Values: Server Default Property: null Importance: medium retention.bytes
This configuration controls the maximum size a partition (which consists of log segments) can grow to before we will discard old log segments to free up space if we are using the "delete" retention policy. By default there is no size limit only a time limit. Since this limit is enforced at the partition level, multiply it by the number of partitions to compute the topic retention in bytes. Additionally, retention.bytes configuration operates independently of "segment.ms" and "segment.bytes" configurations. Moreover, it triggers the rolling of new segment if the retention.bytes is configured to zero.
Type: long Default: -1 Valid Values: Server Default Property: log.retention.bytes Importance: medium retention.ms
This configuration controls the maximum time we will retain a log before we will discard old log segments to free up space if we are using the "delete" retention policy. This represents an SLA on how soon consumers must read their data. If set to -1, no time limit is applied. Additionally, retention.ms configuration operates independently of "segment.ms" and "segment.bytes" configurations. Moreover, it triggers the rolling of new segment if the retention.ms condition is satisfied.
Type: long Default: 604800000 (7 days) Valid Values: [-1,...] Server Default Property: log.retention.ms Importance: medium segment.bytes
This configuration controls the segment file size for the log. Retention and cleaning is always done a file at a time so a larger segment size means fewer files but less granular control over retention.
Type: int Default: 1073741824 (1 gibibyte) Valid Values: [14,...] Server Default Property: log.segment.bytes Importance: medium segment.index.bytes
This configuration controls the size of the index that maps offsets to file positions. We preallocate this index file and shrink it only after log rolls. You generally should not need to change this setting.
Type: int Default: 10485760 (10 mebibytes) Valid Values: [4,...] Server Default Property: log.index.size.max.bytes Importance: medium segment.jitter.ms
The maximum random jitter subtracted from the scheduled segment roll time to avoid thundering herds of segment rolling
Type: long Default: 0 Valid Values: [0,...] Server Default Property: log.roll.jitter.ms Importance: medium segment.ms
This configuration controls the period of time after which Kafka will force the log to roll even if the segment file isn't full to ensure that retention can delete or compact old data.
Type: long Default: 604800000 (7 days) Valid Values: [1,...] Server Default Property: log.roll.ms Importance: medium unclean.leader.election.enable
Indicates whether to enable replicas not in the ISR set to be elected as leader as a last resort, even though doing so may result in data loss.
Note: In KRaft mode, when enabling this config dynamically, it needs to wait for the unclean leader electionthread to trigger election periodically (default is 5 minutes). Please run `kafka-leader-election.sh` with `unclean` option to trigger the unclean leader election immediately if needed.
Type: boolean Default: false Valid Values: Server Default Property: unclean.leader.election.enable Importance: medium
Producer Configs
Below is the configuration of the producer:
key.serializer
Serializer class for key that implements the
org.apache.kafka.common.serialization.Serializerinterface.Type: class Default: Valid Values: Importance: high value.serializer
Serializer class for value that implements the
org.apache.kafka.common.serialization.Serializerinterface.Type: class Default: Valid Values: Importance: high bootstrap.servers
A list of host/port pairs used to establish the initial connection to the Kafka cluster. Clients use this list to bootstrap and discover the full set of Kafka brokers. While the order of servers in the list does not matter, we recommend including more than one server to ensure resilience if any servers are down. This list does not need to contain the entire set of brokers, as Kafka clients automatically manage and update connections to the cluster efficiently. This list must be in the form
host1:port1,host2:port2,....Type: list Default: "" Valid Values: non-null string Importance: high buffer.memory
The total bytes of memory the producer can use to buffer records waiting to be sent to the server. If records are sent faster than they can be delivered to the server the producer will block for
max.block.msafter which it will throw an exception.This setting should correspond roughly to the total memory the producer will use, but is not a hard bound since not all memory the producer uses is used for buffering. Some additional memory will be used for compression (if compression is enabled) as well as for maintaining in-flight requests.
Type: long Default: 33554432 Valid Values: [0,...] Importance: high compression.type
The compression type for all data generated by the producer. The default is none (i.e. no compression). Valid values are
none,gzip,snappy,lz4, orzstd. Compression is of full batches of data, so the efficacy of batching will also impact the compression ratio (more batching means better compression).Type: string Default: none Valid Values: [none, gzip, snappy, lz4, zstd] Importance: high retries
Setting a value greater than zero will cause the client to resend any record whose send fails with a potentially transient error. Note that this retry is no different than if the client resent the record upon receiving the error. Produce requests will be failed before the number of retries has been exhausted if the timeout configured by
delivery.timeout.msexpires first before successful acknowledgement. Users should generally prefer to leave this config unset and instead usedelivery.timeout.msto control retry behavior.Enabling idempotence requires this config value to be greater than 0. If conflicting configurations are set and idempotence is not explicitly enabled, idempotence is disabled.
Allowing retries while setting
enable.idempotencetofalseandmax.in.flight.requests.per.connectionto greater than 1 will potentially change the ordering of records because if two batches are sent to a single partition, and the first fails and is retried but the second succeeds, then the records in the second batch may appear first.Type: int Default: 2147483647 Valid Values: [0,...,2147483647] Importance: high ssl.key.password
The password of the private key in the key store file or the PEM key specified in 'ssl.keystore.key'.
Type: password Default: null Valid Values: Importance: high ssl.keystore.certificate.chain
Certificate chain in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with a list of X.509 certificates
Type: password Default: null Valid Values: Importance: high ssl.keystore.key
Private key in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with PKCS#8 keys. If the key is encrypted, key password must be specified using 'ssl.key.password'
Type: password Default: null Valid Values: Importance: high ssl.keystore.location
The location of the key store file. This is optional for client and can be used for two-way authentication for client.
Type: string Default: null Valid Values: Importance: high ssl.keystore.password
The store password for the key store file. This is optional for client and only needed if 'ssl.keystore.location' is configured. Key store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: high ssl.truststore.certificates
Trusted certificates in the format specified by 'ssl.truststore.type'. Default SSL engine factory supports only PEM format with X.509 certificates.
Type: password Default: null Valid Values: Importance: high ssl.truststore.location
The location of the trust store file.
Type: string Default: null Valid Values: Importance: high ssl.truststore.password
The password for the trust store file. If a password is not set, trust store file configured will still be used, but integrity checking is disabled. Trust store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: high batch.size
The producer will attempt to batch records together into fewer requests whenever multiple records are being sent to the same partition. This helps performance on both the client and the server. This configuration controls the default batch size in bytes.
No attempt will be made to batch records larger than this size.
Requests sent to brokers will contain multiple batches, one for each partition with data available to be sent.
A small batch size will make batching less common and may reduce throughput (a batch size of zero will disable batching entirely). A very large batch size may use memory a bit more wastefully as we will always allocate a buffer of the specified batch size in anticipation of additional records.
Note: This setting gives the upper bound of the batch size to be sent. If we have fewer than this many bytes accumulated for this partition, we will 'linger' for the
linger.mstime waiting for more records to show up. Thislinger.mssetting defaults to 5, which means the producer will wait for 5ms or until the record batch is ofbatch.size(whichever happens first) before sending the record batch. Note that broker backpressure can result in a higher effective linger time than this setting.The default changed from 0 to 5 in Apache Kafka 4.0 as the efficiency gains from larger batches typically result in similar or lower producer latency despite the increased linger.Type: int Default: 16384 Valid Values: [0,...] Importance: medium client.dns.lookup
Controls how the client uses DNS lookups. If set to
use_all_dns_ips, connect to each returned IP address in sequence until a successful connection is established. After a disconnection, the next IP is used. Once all IPs have been used once, the client resolves the IP(s) from the hostname again (both the JVM and the OS cache DNS name lookups, however). If set toresolve_canonical_bootstrap_servers_only, resolve each bootstrap address into a list of canonical names. After the bootstrap phase, this behaves the same asuse_all_dns_ips.Type: string Default: use_all_dns_ips Valid Values: [use_all_dns_ips, resolve_canonical_bootstrap_servers_only] Importance: medium client.id
An id string to pass to the server when making requests. The purpose of this is to be able to track the source of requests beyond just ip/port by allowing a logical application name to be included in server-side request logging.
Type: string Default: "" Valid Values: Importance: medium compression.gzip.level
The compression level to use if compression.type is set to
gzip.Type: int Default: -1 Valid Values: [1,...,9] or -1 Importance: medium compression.lz4.level
The compression level to use if compression.type is set to
lz4.Type: int Default: 9 Valid Values: [1,...,17] Importance: medium compression.zstd.level
The compression level to use if compression.type is set to
zstd.Type: int Default: 3 Valid Values: [-131072,...,22] Importance: medium connections.max.idle.ms
Close idle connections after the number of milliseconds specified by this config.
Type: long Default: 540000 (9 minutes) Valid Values: Importance: medium delivery.timeout.ms
An upper bound on the time to report success or failure after a call to
send()returns. This limits the total time that a record will be delayed prior to sending, the time to await acknowledgement from the broker (if expected), and the time allowed for retriable send failures. The producer may report failure to send a record earlier than this config if either an unrecoverable error is encountered, the retries have been exhausted, or the record is added to a batch which reached an earlier delivery expiration deadline. The value of this config should be greater than or equal to the sum ofrequest.timeout.msandlinger.ms.Type: int Default: 120000 (2 minutes) Valid Values: [0,...] Importance: medium linger.ms
The producer groups together any records that arrive in between request transmissions into a single batched request. Normally this occurs only under load when records arrive faster than they can be sent out. However in some circumstances the client may want to reduce the number of requests even under moderate load. This setting accomplishes this by adding a small amount of artificial delay—that is, rather than immediately sending out a record, the producer will wait for up to the given delay to allow other records to be sent so that the sends can be batched together. This can be thought of as analogous to Nagle's algorithm in TCP. This setting gives the upper bound on the delay for batching: once we get
batch.sizeworth of records for a partition it will be sent immediately regardless of this setting, however if we have fewer than this many bytes accumulated for this partition we will 'linger' for the specified time waiting for more records to show up. This setting defaults to 5 (i.e. 5ms delay). Increasinglinger.ms=50, for example, would have the effect of reducing the number of requests sent but would add up to 50ms of latency to records sent in the absence of load.The default changed from 0 to 5 in Apache Kafka 4.0 as the efficiency gains from larger batches typically result in similar or lower producer latency despite the increased linger.Type: long Default: 5 Valid Values: [0,...] Importance: medium max.block.ms
The configuration controls how long the
KafkaProducer'ssend(),partitionsFor(),initTransactions(),sendOffsetsToTransaction(),commitTransaction()andabortTransaction()methods will block. Forsend()this timeout bounds the total time waiting for both metadata fetch and buffer allocation (blocking in the user-supplied serializers or partitioner is not counted against this timeout). ForpartitionsFor()this timeout bounds the time spent waiting for metadata if it is unavailable. The transaction-related methods always block, but may timeout if the transaction coordinator could not be discovered or did not respond within the timeout.Type: long Default: 60000 (1 minute) Valid Values: [0,...] Importance: medium max.request.size
The maximum size of a request in bytes. This setting will limit the number of record batches the producer will send in a single request to avoid sending huge requests. This is also effectively a cap on the maximum uncompressed record batch size. Note that the server has its own cap on the record batch size (after compression if compression is enabled) which may be different from this.
Type: int Default: 1048576 Valid Values: [0,...] Importance: medium partitioner.class
Determines which partition to send a record to when records are produced. Available options are:
- If not set, the default partitioning logic is used. This strategy send records to a partition until at least batch.size bytes is produced to the partition. It works with the strategy:
- If no partition is specified but a key is present, choose a partition based on a hash of the key.
- If no partition or key is present, choose the sticky partition that changes when at least batch.size bytes are produced to the partition.
org.apache.kafka.clients.producer.RoundRobinPartitioner: A partitioning strategy where each record in a series of consecutive records is sent to a different partition, regardless of whether the 'key' is provided or not, until partitions run out and the process starts over again. Note: There's a known issue that will cause uneven distribution when a new batch is created. See KAFKA-9965 for more detail.
Implementing the
org.apache.kafka.clients.producer.Partitionerinterface allows you to plug in a custom partitioner.Type: class Default: null Valid Values: Importance: medium - If not set, the default partitioning logic is used. This strategy send records to a partition until at least batch.size bytes is produced to the partition. It works with the strategy:
partitioner.ignore.keys
When set to 'true' the producer won't use record keys to choose a partition. If 'false', producer would choose a partition based on a hash of the key when a key is present. Note: this setting has no effect if a custom partitioner is used.
Type: boolean Default: false Valid Values: Importance: medium receive.buffer.bytes
The size of the TCP receive buffer (SO_RCVBUF) to use when reading data. If the value is -1, the OS default will be used.
Type: int Default: 32768 (32 kibibytes) Valid Values: [-1,...] Importance: medium request.timeout.ms
The configuration controls the maximum amount of time the client will wait for the response of a request. If the response is not received before the timeout elapses the client will resend the request if necessary or fail the request if retries are exhausted. This should be larger than
replica.lag.time.max.ms(a broker configuration) to reduce the possibility of message duplication due to unnecessary producer retries.Type: int Default: 30000 (30 seconds) Valid Values: [0,...] Importance: medium sasl.client.callback.handler.class
The fully qualified name of a SASL client callback handler class that implements the AuthenticateCallbackHandler interface.
Type: class Default: null Valid Values: Importance: medium sasl.jaas.config
JAAS login context parameters for SASL connections in the format used by JAAS configuration files. JAAS configuration file format is described here. The format for the value is:
loginModuleClass controlFlag (optionName=optionValue)*;. For brokers, the config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.jaas.config=com.example.ScramLoginModule required;Type: password Default: null Valid Values: Importance: medium sasl.kerberos.service.name
The Kerberos principal name that Kafka runs as. This can be defined either in Kafka's JAAS config or in Kafka's config.
Type: string Default: null Valid Values: Importance: medium sasl.login.callback.handler.class
The fully qualified name of a SASL login callback handler class that implements the AuthenticateCallbackHandler interface. For brokers, login callback handler config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.callback.handler.class=com.example.CustomScramLoginCallbackHandler
Type: class Default: null Valid Values: Importance: medium sasl.login.class
The fully qualified name of a class that implements the Login interface. For brokers, login config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.class=com.example.CustomScramLogin
Type: class Default: null Valid Values: Importance: medium sasl.mechanism
SASL mechanism used for client connections. This may be any mechanism for which a security provider is available. GSSAPI is the default mechanism.
Type: string Default: GSSAPI Valid Values: Importance: medium sasl.oauthbearer.jwks.endpoint.url
The OAuth/OIDC provider URL from which the provider's JWKS (JSON Web Key Set) can be retrieved. The URL can be HTTP(S)-based or file-based. If the URL is HTTP(S)-based, the JWKS data will be retrieved from the OAuth/OIDC provider via the configured URL on broker startup. All then-current keys will be cached on the broker for incoming requests. If an authentication request is received for a JWT that includes a "kid" header claim value that isn't yet in the cache, the JWKS endpoint will be queried again on demand. However, the broker polls the URL every sasl.oauthbearer.jwks.endpoint.refresh.ms milliseconds to refresh the cache with any forthcoming keys before any JWT requests that include them are received. If the URL is file-based, the broker will load the JWKS file from a configured location on startup. In the event that the JWT includes a "kid" header value that isn't in the JWKS file, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: medium sasl.oauthbearer.token.endpoint.url
The URL for the OAuth/OIDC identity provider. If the URL is HTTP(S)-based, it is the issuer's token endpoint URL to which requests will be made to login based on the configuration in sasl.jaas.config. If the URL is file-based, it specifies a file containing an access token (in JWT serialized form) issued by the OAuth/OIDC identity provider to use for authorization.
Type: string Default: null Valid Values: Importance: medium security.protocol
Protocol used to communicate with brokers.
Type: string Default: PLAINTEXT Valid Values: (case insensitive) [SASL_SSL, PLAINTEXT, SSL, SASL_PLAINTEXT] Importance: medium send.buffer.bytes
The size of the TCP send buffer (SO_SNDBUF) to use when sending data. If the value is -1, the OS default will be used.
Type: int Default: 131072 (128 kibibytes) Valid Values: [-1,...] Importance: medium socket.connection.setup.timeout.max.ms
The maximum amount of time the client will wait for the socket connection to be established. The connection setup timeout will increase exponentially for each consecutive connection failure up to this maximum. To avoid connection storms, a randomization factor of 0.2 will be applied to the timeout resulting in a random range between 20% below and 20% above the computed value.
Type: long Default: 30000 (30 seconds) Valid Values: Importance: medium socket.connection.setup.timeout.ms
The amount of time the client will wait for the socket connection to be established. If the connection is not built before the timeout elapses, clients will close the socket channel. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the
socket.connection.setup.timeout.max.msvalue.Type: long Default: 10000 (10 seconds) Valid Values: Importance: medium ssl.enabled.protocols
The list of protocols enabled for SSL connections. The default is 'TLSv1.2,TLSv1.3'. This means that clients and servers will prefer TLSv1.3 if both support it and fallback to TLSv1.2 otherwise (assuming both support at least TLSv1.2). This default should be fine for most use cases. Also see the config documentation for `ssl.protocol` to understand how it can impact the TLS version negotiation behavior.
Type: list Default: TLSv1.2,TLSv1.3 Valid Values: Importance: medium ssl.keystore.type
The file format of the key store file. This is optional for client. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium ssl.protocol
The SSL protocol used to generate the SSLContext. The default is 'TLSv1.3', which should be fine for most use cases. A typical alternative to the default is 'TLSv1.2'. Allowed values for this config are dependent on the JVM. Clients using the defaults for this config and 'ssl.enabled.protocols' will downgrade to 'TLSv1.2' if the server does not support 'TLSv1.3'. If this config is set to 'TLSv1.2', however, clients will not use 'TLSv1.3' even if it is one of the values in `ssl.enabled.protocols` and the server only supports 'TLSv1.3'.
Type: string Default: TLSv1.3 Valid Values: Importance: medium ssl.provider
The name of the security provider used for SSL connections. Default value is the default security provider of the JVM.
Type: string Default: null Valid Values: Importance: medium ssl.truststore.type
The file format of the trust store file. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium acks
The number of acknowledgments the producer requires the leader to have received before considering a request complete. This controls the durability of records that are sent. The following settings are allowed:
acks=0If set to zero then the producer will not wait for any acknowledgment from the server at all. The record will be immediately added to the socket buffer and considered sent. No guarantee can be made that the server has received the record in this case, and theretriesconfiguration will not take effect (as the client won't generally know of any failures). The offset given back for each record will always be set to-1.acks=1This will mean the leader will write the record to its local log but will respond without awaiting full acknowledgement from all followers. In this case should the leader fail immediately after acknowledging the record but before the followers have replicated it then the record will be lost.acks=allThis means the leader will wait for the full set of in-sync replicas to acknowledge the record. This guarantees that the record will not be lost as long as at least one in-sync replica remains alive. This is the strongest available guarantee. This is equivalent to the acks=-1 setting.
Note that enabling idempotence requires this config value to be 'all'. If conflicting configurations are set and idempotence is not explicitly enabled, idempotence is disabled.
Type: string Default: all Valid Values: [all, -1, 0, 1] Importance: low enable.idempotence
When set to 'true', the producer will ensure that exactly one copy of each message is written in the stream. If 'false', producer retries due to broker failures, etc., may write duplicates of the retried message in the stream. Note that enabling idempotence requires
max.in.flight.requests.per.connectionto be less than or equal to 5 (with message ordering preserved for any allowable value),retriesto be greater than 0, andacksmust be 'all'.Idempotence is enabled by default if no conflicting configurations are set. If conflicting configurations are set and idempotence is not explicitly enabled, idempotence is disabled. If idempotence is explicitly enabled and conflicting configurations are set, a
ConfigExceptionis thrown.Type: boolean Default: true Valid Values: Importance: low enable.metrics.push
Whether to enable pushing of client metrics to the cluster, if the cluster has a client metrics subscription which matches this client.
Type: boolean Default: true Valid Values: Importance: low interceptor.classes
A list of classes to use as interceptors. Implementing the
org.apache.kafka.clients.producer.ProducerInterceptorinterface allows you to intercept (and possibly mutate) the records received by the producer before they are published to the Kafka cluster. By default, there are no interceptors.Type: list Default: "" Valid Values: non-null string Importance: low max.in.flight.requests.per.connection
The maximum number of unacknowledged requests the client will send on a single connection before blocking. Note that if this configuration is set to be greater than 1 and
enable.idempotenceis set to false, there is a risk of message reordering after a failed send due to retries (i.e., if retries are enabled); if retries are disabled or ifenable.idempotenceis set to true, ordering will be preserved. Additionally, enabling idempotence requires the value of this configuration to be less than or equal to 5, because broker only retains at most 5 batches for each producer. If the value is more than 5, previous batches may be removed on broker side.Type: int Default: 5 Valid Values: [1,...] Importance: low metadata.max.age.ms
The period of time in milliseconds after which we force a refresh of metadata even if we haven't seen any partition leadership changes to proactively discover any new brokers or partitions.
Type: long Default: 300000 (5 minutes) Valid Values: [0,...] Importance: low metadata.max.idle.ms
Controls how long the producer will cache metadata for a topic that's idle. If the elapsed time since a topic was last produced to exceeds the metadata idle duration, then the topic's metadata is forgotten and the next access to it will force a metadata fetch request.
Type: long Default: 300000 (5 minutes) Valid Values: [5000,...] Importance: low metadata.recovery.rebootstrap.trigger.ms
If a client configured to rebootstrap using
metadata.recovery.strategy=rebootstrapis unable to obtain metadata from any of the brokers in the last known metadata for this interval, client repeats the bootstrap process usingbootstrap.serversconfiguration.Type: long Default: 300000 (5 minutes) Valid Values: [0,...] Importance: low metadata.recovery.strategy
Controls how the client recovers when none of the brokers known to it is available. If set to
none, the client fails. If set torebootstrap, the client repeats the bootstrap process usingbootstrap.servers. Rebootstrapping is useful when a client communicates with brokers so infrequently that the set of brokers may change entirely before the client refreshes metadata. Metadata recovery is triggered when all last-known brokers appear unavailable simultaneously. Brokers appear unavailable when disconnected and no current retry attempt is in-progress. Consider increasingreconnect.backoff.msandreconnect.backoff.max.msand decreasingsocket.connection.setup.timeout.msandsocket.connection.setup.timeout.max.msfor the client. Rebootstrap is also triggered if connection cannot be established to any of the brokers formetadata.recovery.rebootstrap.trigger.msmilliseconds or if server requests rebootstrap.Type: string Default: rebootstrap Valid Values: (case insensitive) [REBOOTSTRAP, NONE] Importance: low metric.reporters
A list of classes to use as metrics reporters. Implementing the
org.apache.kafka.common.metrics.MetricsReporterinterface allows plugging in classes that will be notified of new metric creation.Type: list Default: org.apache.kafka.common.metrics.JmxReporter Valid Values: non-null string Importance: low metrics.num.samples
The number of samples maintained to compute metrics.
Type: int Default: 2 Valid Values: [1,...] Importance: low metrics.recording.level
The highest recording level for metrics. It has three levels for recording metrics - info, debug, and trace.
INFO level records only essential metrics necessary for monitoring system performance and health. It collects vital data without gathering too much detail, making it suitable for production environments where minimal overhead is desired.
DEBUG level records most metrics, providing more detailed information about the system's operation. It's useful for development and testing environments where you need deeper insights to debug and fine-tune the application.
TRACE level records all possible metrics, capturing every detail about the system's performance and operation. It's best for controlled environments where in-depth analysis is required, though it can introduce significant overhead.Type: string Default: INFO Valid Values: [INFO, DEBUG, TRACE] Importance: low metrics.sample.window.ms
The window of time a metrics sample is computed over.
Type: long Default: 30000 (30 seconds) Valid Values: [0,...] Importance: low partitioner.adaptive.partitioning.enable
When set to 'true', the producer will try to adapt to broker performance and produce more messages to partitions hosted on faster brokers. If 'false', producer will try to distribute messages uniformly. Note: this setting has no effect if a custom partitioner is used
Type: boolean Default: true Valid Values: Importance: low partitioner.availability.timeout.ms
If a broker cannot process produce requests from a partition for
partitioner.availability.timeout.mstime, the partitioner treats that partition as not available. If the value is 0, this logic is disabled. Note: this setting has no effect if a custom partitioner is used orpartitioner.adaptive.partitioning.enableis set to 'false'Type: long Default: 0 Valid Values: [0,...] Importance: low reconnect.backoff.max.ms
The maximum amount of time in milliseconds to wait when reconnecting to a broker that has repeatedly failed to connect. If provided, the backoff per host will increase exponentially for each consecutive connection failure, up to this maximum. After calculating the backoff increase, 20% random jitter is added to avoid connection storms.
Type: long Default: 1000 (1 second) Valid Values: [0,...] Importance: low reconnect.backoff.ms
The base amount of time to wait before attempting to reconnect to a given host. This avoids repeatedly connecting to a host in a tight loop. This backoff applies to all connection attempts by the client to a broker. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the
reconnect.backoff.max.msvalue.Type: long Default: 50 Valid Values: [0,...] Importance: low retry.backoff.max.ms
The maximum amount of time in milliseconds to wait when retrying a request to the broker that has repeatedly failed. If provided, the backoff per client will increase exponentially for each failed request, up to this maximum. To prevent all clients from being synchronized upon retry, a randomized jitter with a factor of 0.2 will be applied to the backoff, resulting in the backoff falling within a range between 20% below and 20% above the computed value. If
retry.backoff.msis set to be higher thanretry.backoff.max.ms, thenretry.backoff.max.mswill be used as a constant backoff from the beginning without any exponential increaseType: long Default: 1000 (1 second) Valid Values: [0,...] Importance: low retry.backoff.ms
The amount of time to wait before attempting to retry a failed request to a given topic partition. This avoids repeatedly sending requests in a tight loop under some failure scenarios. This value is the initial backoff value and will increase exponentially for each failed request, up to the
retry.backoff.max.msvalue.Type: long Default: 100 Valid Values: [0,...] Importance: low sasl.kerberos.kinit.cmd
Kerberos kinit command path.
Type: string Default: /usr/bin/kinit Valid Values: Importance: low sasl.kerberos.min.time.before.relogin
Login thread sleep time between refresh attempts.
Type: long Default: 60000 Valid Values: Importance: low sasl.kerberos.ticket.renew.jitter
Percentage of random jitter added to the renewal time.
Type: double Default: 0.05 Valid Values: Importance: low sasl.kerberos.ticket.renew.window.factor
Login thread will sleep until the specified window factor of time from last refresh to ticket's expiry has been reached, at which time it will try to renew the ticket.
Type: double Default: 0.8 Valid Values: Importance: low sasl.login.connect.timeout.ms
The (optional) value in milliseconds for the external authentication provider connection timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low sasl.login.read.timeout.ms
The (optional) value in milliseconds for the external authentication provider read timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low sasl.login.refresh.buffer.seconds
The amount of buffer time before credential expiration to maintain when refreshing a credential, in seconds. If a refresh would otherwise occur closer to expiration than the number of buffer seconds then the refresh will be moved up to maintain as much of the buffer time as possible. Legal values are between 0 and 3600 (1 hour); a default value of 300 (5 minutes) is used if no value is specified. This value and sasl.login.refresh.min.period.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 300 Valid Values: [0,...,3600] Importance: low sasl.login.refresh.min.period.seconds
The desired minimum time for the login refresh thread to wait before refreshing a credential, in seconds. Legal values are between 0 and 900 (15 minutes); a default value of 60 (1 minute) is used if no value is specified. This value and sasl.login.refresh.buffer.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 60 Valid Values: [0,...,900] Importance: low sasl.login.refresh.window.factor
Login refresh thread will sleep until the specified window factor relative to the credential's lifetime has been reached, at which time it will try to refresh the credential. Legal values are between 0.5 (50%) and 1.0 (100%) inclusive; a default value of 0.8 (80%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.8 Valid Values: [0.5,...,1.0] Importance: low sasl.login.refresh.window.jitter
The maximum amount of random jitter relative to the credential's lifetime that is added to the login refresh thread's sleep time. Legal values are between 0 and 0.25 (25%) inclusive; a default value of 0.05 (5%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.05 Valid Values: [0.0,...,0.25] Importance: low sasl.login.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low sasl.login.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 100 Valid Values: Importance: low sasl.oauthbearer.clock.skew.seconds
The (optional) value in seconds to allow for differences between the time of the OAuth/OIDC identity provider and the broker.
Type: int Default: 30 Valid Values: Importance: low sasl.oauthbearer.expected.audience
The (optional) comma-delimited setting for the broker to use to verify that the JWT was issued for one of the expected audiences. The JWT will be inspected for the standard OAuth "aud" claim and if this value is set, the broker will match the value from JWT's "aud" claim to see if there is an exact match. If there is no match, the broker will reject the JWT and authentication will fail.
Type: list Default: null Valid Values: Importance: low sasl.oauthbearer.expected.issuer
The (optional) setting for the broker to use to verify that the JWT was created by the expected issuer. The JWT will be inspected for the standard OAuth "iss" claim and if this value is set, the broker will match it exactly against what is in the JWT's "iss" claim. If there is no match, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: low sasl.oauthbearer.header.urlencode
The (optional) setting to enable the OAuth client to URL-encode the client_id and client_secret in the authorization header in accordance with RFC6749, see here for more details. The default value is set to 'false' for backward compatibility
Type: boolean Default: false Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.refresh.ms
The (optional) value in milliseconds for the broker to wait between refreshing its JWKS (JSON Web Key Set) cache that contains the keys to verify the signature of the JWT.
Type: long Default: 3600000 (1 hour) Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between attempts to retrieve the JWKS (JSON Web Key Set) from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between JWKS (JSON Web Key Set) retrieval attempts from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 100 Valid Values: Importance: low sasl.oauthbearer.scope.claim.name
The OAuth claim for the scope is often named "scope", but this (optional) setting can provide a different name to use for the scope included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: scope Valid Values: Importance: low sasl.oauthbearer.sub.claim.name
The OAuth claim for the subject is often named "sub", but this (optional) setting can provide a different name to use for the subject included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: sub Valid Values: Importance: low security.providers
A list of configurable creator classes each returning a provider implementing security algorithms. These classes should implement the
org.apache.kafka.common.security.auth.SecurityProviderCreatorinterface.Type: string Default: null Valid Values: Importance: low ssl.cipher.suites
A list of cipher suites. This is a named combination of authentication, encryption, MAC and key exchange algorithm used to negotiate the security settings for a network connection using TLS or SSL network protocol. By default all the available cipher suites are supported.
Type: list Default: null Valid Values: Importance: low ssl.endpoint.identification.algorithm
The endpoint identification algorithm to validate server hostname using server certificate.
Type: string Default: https Valid Values: Importance: low ssl.engine.factory.class
The class of type org.apache.kafka.common.security.auth.SslEngineFactory to provide SSLEngine objects. Default value is org.apache.kafka.common.security.ssl.DefaultSslEngineFactory. Alternatively, setting this to org.apache.kafka.common.security.ssl.CommonNameLoggingSslEngineFactory will log the common name of expired SSL certificates used by clients to authenticate at any of the brokers with log level INFO. Note that this will cause a tiny delay during establishment of new connections from mTLS clients to brokers due to the extra code for examining the certificate chain provided by the client. Note further that the implementation uses a custom truststore based on the standard Java truststore and thus might be considered a security risk due to not being as mature as the standard one.
Type: class Default: null Valid Values: Importance: low ssl.keymanager.algorithm
The algorithm used by key manager factory for SSL connections. Default value is the key manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: SunX509 Valid Values: Importance: low ssl.secure.random.implementation
The SecureRandom PRNG implementation to use for SSL cryptography operations.
Type: string Default: null Valid Values: Importance: low ssl.trustmanager.algorithm
The algorithm used by trust manager factory for SSL connections. Default value is the trust manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: PKIX Valid Values: Importance: low transaction.timeout.ms
The maximum amount of time in milliseconds that a transaction will remain open before the coordinator proactively aborts it. The start of the transaction is set at the time that the first partition is added to it. If this value is larger than the
transaction.max.timeout.mssetting in the broker, the request will fail with aInvalidTxnTimeoutExceptionerror.Type: int Default: 60000 (1 minute) Valid Values: Importance: low transactional.id
The TransactionalId to use for transactional delivery. This enables reliability semantics which span multiple producer sessions since it allows the client to guarantee that transactions using the same TransactionalId have been completed prior to starting any new transactions. If no TransactionalId is provided, then the producer is limited to idempotent delivery. If a TransactionalId is configured,
enable.idempotenceis implied. By default the TransactionId is not configured, which means transactions cannot be used. Note that, by default, transactions require a cluster of at least three brokers which is the recommended setting for production; for development you can change this, by adjusting broker settingtransaction.state.log.replication.factor.Type: string Default: null Valid Values: non-empty string Importance: low
Consumer Configs
Below is the configuration for the consumer:
key.deserializer
Deserializer class for key that implements the
org.apache.kafka.common.serialization.Deserializerinterface.Type: class Default: Valid Values: Importance: high value.deserializer
Deserializer class for value that implements the
org.apache.kafka.common.serialization.Deserializerinterface.Type: class Default: Valid Values: Importance: high bootstrap.servers
A list of host/port pairs used to establish the initial connection to the Kafka cluster. Clients use this list to bootstrap and discover the full set of Kafka brokers. While the order of servers in the list does not matter, we recommend including more than one server to ensure resilience if any servers are down. This list does not need to contain the entire set of brokers, as Kafka clients automatically manage and update connections to the cluster efficiently. This list must be in the form
host1:port1,host2:port2,....Type: list Default: "" Valid Values: non-null string Importance: high fetch.min.bytes
The minimum amount of data the server should return for a fetch request. If insufficient data is available the request will wait for that much data to accumulate before answering the request. The default setting of 1 byte means that fetch requests are answered as soon as that many byte(s) of data is available or the fetch request times out waiting for data to arrive. Setting this to a larger value will cause the server to wait for larger amounts of data to accumulate which can improve server throughput a bit at the cost of some additional latency.
Type: int Default: 1 Valid Values: [0,...] Importance: high group.id
A unique string that identifies the consumer group this consumer belongs to. This property is required if the consumer uses either the group management functionality by using
subscribe(topic)or the Kafka-based offset management strategy.Type: string Default: null Valid Values: Importance: high group.protocol
The group protocol consumer should use. We currently support "classic" or "consumer". If "consumer" is specified, then the consumer group protocol will be used. Otherwise, the classic group protocol will be used.
Type: string Default: classic Valid Values: (case insensitive) [CONSUMER, CLASSIC] Importance: high heartbeat.interval.ms
The expected time between heartbeats to the consumer coordinator when using Kafka's group management facilities. Heartbeats are used to ensure that the consumer's session stays active and to facilitate rebalancing when new consumers join or leave the group. The value must be set lower than
session.timeout.ms, but typically should be set no higher than 1/3 of that value. It can be adjusted even lower to control the expected time for normal rebalances.Type: int Default: 3000 (3 seconds) Valid Values: Importance: high max.partition.fetch.bytes
The maximum amount of data per-partition the server will return. Records are fetched in batches by the consumer. If the first record batch in the first non-empty partition of the fetch is larger than this limit, the batch will still be returned to ensure that the consumer can make progress. The maximum record batch size accepted by the broker is defined via
message.max.bytes(broker config) ormax.message.bytes(topic config). See fetch.max.bytes for limiting the consumer request size.Type: int Default: 1048576 (1 mebibyte) Valid Values: [0,...] Importance: high session.timeout.ms
The timeout used to detect client failures when using Kafka's group management facility. The client sends periodic heartbeats to indicate its liveness to the broker. If no heartbeats are received by the broker before the expiration of this session timeout, then the broker will remove this client from the group and initiate a rebalance. Note that the value must be in the allowable range as configured in the broker configuration by
group.min.session.timeout.msandgroup.max.session.timeout.ms. Note that this configuration is not supported whengroup.protocolis set to "consumer".Type: int Default: 45000 (45 seconds) Valid Values: Importance: high ssl.key.password
The password of the private key in the key store file or the PEM key specified in 'ssl.keystore.key'.
Type: password Default: null Valid Values: Importance: high ssl.keystore.certificate.chain
Certificate chain in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with a list of X.509 certificates
Type: password Default: null Valid Values: Importance: high ssl.keystore.key
Private key in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with PKCS#8 keys. If the key is encrypted, key password must be specified using 'ssl.key.password'
Type: password Default: null Valid Values: Importance: high ssl.keystore.location
The location of the key store file. This is optional for client and can be used for two-way authentication for client.
Type: string Default: null Valid Values: Importance: high ssl.keystore.password
The store password for the key store file. This is optional for client and only needed if 'ssl.keystore.location' is configured. Key store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: high ssl.truststore.certificates
Trusted certificates in the format specified by 'ssl.truststore.type'. Default SSL engine factory supports only PEM format with X.509 certificates.
Type: password Default: null Valid Values: Importance: high ssl.truststore.location
The location of the trust store file.
Type: string Default: null Valid Values: Importance: high ssl.truststore.password
The password for the trust store file. If a password is not set, trust store file configured will still be used, but integrity checking is disabled. Trust store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: high allow.auto.create.topics
Allow automatic topic creation on the broker when subscribing to or assigning a topic. A topic being subscribed to will be automatically created only if the broker allows for it using `auto.create.topics.enable` broker configuration. This configuration must be set to `true` when using brokers older than 0.11.0
Type: boolean Default: true Valid Values: Importance: medium auto.offset.reset
What to do when there is no initial offset in Kafka or if the current offset does not exist any more on the server (e.g. because that data has been deleted):
- earliest: automatically reset the offset to the earliest offset
- latest: automatically reset the offset to the latest offset
- by_duration:<duration>: automatically reset the offset to a configured <duration> from the current timestamp. <duration> must be specified in ISO8601 format (PnDTnHnMn.nS). Negative duration is not allowed.
- none: throw exception to the consumer if no previous offset is found for the consumer's group
- anything else: throw exception to the consumer.
Note that altering partition numbers while setting this config to latest may cause message delivery loss since producers could start to send messages to newly added partitions (i.e. no initial offsets exist yet) before consumers reset their offsets.
Type: string Default: latest Valid Values: [latest, earliest, none, by_duration:PnDTnHnMn.nS] Importance: medium client.dns.lookup
Controls how the client uses DNS lookups. If set to
use_all_dns_ips, connect to each returned IP address in sequence until a successful connection is established. After a disconnection, the next IP is used. Once all IPs have been used once, the client resolves the IP(s) from the hostname again (both the JVM and the OS cache DNS name lookups, however). If set toresolve_canonical_bootstrap_servers_only, resolve each bootstrap address into a list of canonical names. After the bootstrap phase, this behaves the same asuse_all_dns_ips.Type: string Default: use_all_dns_ips Valid Values: [use_all_dns_ips, resolve_canonical_bootstrap_servers_only] Importance: medium connections.max.idle.ms
Close idle connections after the number of milliseconds specified by this config.
Type: long Default: 540000 (9 minutes) Valid Values: Importance: medium default.api.timeout.ms
Specifies the timeout (in milliseconds) for client APIs. This configuration is used as the default timeout for all client operations that do not specify a
timeoutparameter.Type: int Default: 60000 (1 minute) Valid Values: [0,...] Importance: medium enable.auto.commit
If true the consumer's offset will be periodically committed in the background.
Type: boolean Default: true Valid Values: Importance: medium exclude.internal.topics
Whether internal topics matching a subscribed pattern should be excluded from the subscription. It is always possible to explicitly subscribe to an internal topic.
Type: boolean Default: true Valid Values: Importance: medium fetch.max.bytes
The maximum amount of data the server should return for a fetch request. Records are fetched in batches by the consumer, and if the first record batch in the first non-empty partition of the fetch is larger than this value, the record batch will still be returned to ensure that the consumer can make progress. As such, this is not a absolute maximum. The maximum record batch size accepted by the broker is defined via
message.max.bytes(broker config) ormax.message.bytes(topic config). Note that the consumer performs multiple fetches in parallel.Type: int Default: 52428800 (50 mebibytes) Valid Values: [0,...] Importance: medium group.instance.id
A unique identifier of the consumer instance provided by the end user. Only non-empty strings are permitted. If set, the consumer is treated as a static member, which means that only one instance with this ID is allowed in the consumer group at any time. This can be used in combination with a larger session timeout to avoid group rebalances caused by transient unavailability (e.g. process restarts). If not set, the consumer will join the group as a dynamic member, which is the traditional behavior.
Type: string Default: null Valid Values: non-empty string Importance: medium group.remote.assignor
The name of the server-side assignor to use. If not specified, the group coordinator will pick the first assignor defined in the broker config group.consumer.assignors.This configuration is applied only if
group.protocolis set to "consumer".Type: string Default: null Valid Values: Importance: medium isolation.level
Controls how to read messages written transactionally. If set to
read_committed, consumer.poll() will only return transactional messages which have been committed. If set toread_uncommitted(the default), consumer.poll() will return all messages, even transactional messages which have been aborted. Non-transactional messages will be returned unconditionally in either mode.Messages will always be returned in offset order. Hence, in
read_committedmode, consumer.poll() will only return messages up to the last stable offset (LSO), which is the one less than the offset of the first open transaction. In particular any messages appearing after messages belonging to ongoing transactions will be withheld until the relevant transaction has been completed. As a result,read_committedconsumers will not be able to read up to the high watermark when there are in flight transactions.Further, when in
read_committedthe seekToEnd method will return the LSOType: string Default: read_uncommitted Valid Values: [read_committed, read_uncommitted] Importance: medium max.poll.interval.ms
The maximum delay between invocations of poll() when using consumer group management. This places an upper bound on the amount of time that the consumer can be idle before fetching more records. If poll() is not called before expiration of this timeout, then the consumer is considered failed and the group will rebalance in order to reassign the partitions to another member. For consumers using a non-null
group.instance.idwhich reach this timeout, partitions will not be immediately reassigned. Instead, the consumer will stop sending heartbeats and partitions will be reassigned after expiration ofsession.timeout.ms. This mirrors the behavior of a static consumer which has shutdown.Type: int Default: 300000 (5 minutes) Valid Values: [1,...] Importance: medium max.poll.records
The maximum number of records returned in a single call to poll(). Note, that
max.poll.recordsdoes not impact the underlying fetching behavior. The consumer will cache the records from each fetch request and returns them incrementally from each poll.Type: int Default: 500 Valid Values: [1,...] Importance: medium partition.assignment.strategy
A list of class names or class types, ordered by preference, of supported partition assignment strategies that the client will use to distribute partition ownership amongst consumer instances when group management is used. Available options are:
org.apache.kafka.clients.consumer.RangeAssignor: Assigns partitions on a per-topic basis.org.apache.kafka.clients.consumer.RoundRobinAssignor: Assigns partitions to consumers in a round-robin fashion.org.apache.kafka.clients.consumer.StickyAssignor: Guarantees an assignment that is maximally balanced while preserving as many existing partition assignments as possible.org.apache.kafka.clients.consumer.CooperativeStickyAssignor: Follows the same StickyAssignor logic, but allows for cooperative rebalancing.
The default assignor is [RangeAssignor, CooperativeStickyAssignor], which will use the RangeAssignor by default, but allows upgrading to the CooperativeStickyAssignor with just a single rolling bounce that removes the RangeAssignor from the list.
Implementing the
org.apache.kafka.clients.consumer.ConsumerPartitionAssignorinterface allows you to plug in a custom assignment strategy.Type: list Default: class org.apache.kafka.clients.consumer.RangeAssignor,class org.apache.kafka.clients.consumer.CooperativeStickyAssignor Valid Values: non-null string Importance: medium receive.buffer.bytes
The size of the TCP receive buffer (SO_RCVBUF) to use when reading data. If the value is -1, the OS default will be used.
Type: int Default: 65536 (64 kibibytes) Valid Values: [-1,...] Importance: medium request.timeout.ms
The configuration controls the maximum amount of time the client will wait for the response of a request. If the response is not received before the timeout elapses the client will resend the request if necessary or fail the request if retries are exhausted.
Type: int Default: 30000 (30 seconds) Valid Values: [0,...] Importance: medium sasl.client.callback.handler.class
The fully qualified name of a SASL client callback handler class that implements the AuthenticateCallbackHandler interface.
Type: class Default: null Valid Values: Importance: medium sasl.jaas.config
JAAS login context parameters for SASL connections in the format used by JAAS configuration files. JAAS configuration file format is described here. The format for the value is:
loginModuleClass controlFlag (optionName=optionValue)*;. For brokers, the config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.jaas.config=com.example.ScramLoginModule required;Type: password Default: null Valid Values: Importance: medium sasl.kerberos.service.name
The Kerberos principal name that Kafka runs as. This can be defined either in Kafka's JAAS config or in Kafka's config.
Type: string Default: null Valid Values: Importance: medium sasl.login.callback.handler.class
The fully qualified name of a SASL login callback handler class that implements the AuthenticateCallbackHandler interface. For brokers, login callback handler config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.callback.handler.class=com.example.CustomScramLoginCallbackHandler
Type: class Default: null Valid Values: Importance: medium sasl.login.class
The fully qualified name of a class that implements the Login interface. For brokers, login config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.class=com.example.CustomScramLogin
Type: class Default: null Valid Values: Importance: medium sasl.mechanism
SASL mechanism used for client connections. This may be any mechanism for which a security provider is available. GSSAPI is the default mechanism.
Type: string Default: GSSAPI Valid Values: Importance: medium sasl.oauthbearer.jwks.endpoint.url
The OAuth/OIDC provider URL from which the provider's JWKS (JSON Web Key Set) can be retrieved. The URL can be HTTP(S)-based or file-based. If the URL is HTTP(S)-based, the JWKS data will be retrieved from the OAuth/OIDC provider via the configured URL on broker startup. All then-current keys will be cached on the broker for incoming requests. If an authentication request is received for a JWT that includes a "kid" header claim value that isn't yet in the cache, the JWKS endpoint will be queried again on demand. However, the broker polls the URL every sasl.oauthbearer.jwks.endpoint.refresh.ms milliseconds to refresh the cache with any forthcoming keys before any JWT requests that include them are received. If the URL is file-based, the broker will load the JWKS file from a configured location on startup. In the event that the JWT includes a "kid" header value that isn't in the JWKS file, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: medium sasl.oauthbearer.token.endpoint.url
The URL for the OAuth/OIDC identity provider. If the URL is HTTP(S)-based, it is the issuer's token endpoint URL to which requests will be made to login based on the configuration in sasl.jaas.config. If the URL is file-based, it specifies a file containing an access token (in JWT serialized form) issued by the OAuth/OIDC identity provider to use for authorization.
Type: string Default: null Valid Values: Importance: medium security.protocol
Protocol used to communicate with brokers.
Type: string Default: PLAINTEXT Valid Values: (case insensitive) [SASL_SSL, PLAINTEXT, SSL, SASL_PLAINTEXT] Importance: medium send.buffer.bytes
The size of the TCP send buffer (SO_SNDBUF) to use when sending data. If the value is -1, the OS default will be used.
Type: int Default: 131072 (128 kibibytes) Valid Values: [-1,...] Importance: medium socket.connection.setup.timeout.max.ms
The maximum amount of time the client will wait for the socket connection to be established. The connection setup timeout will increase exponentially for each consecutive connection failure up to this maximum. To avoid connection storms, a randomization factor of 0.2 will be applied to the timeout resulting in a random range between 20% below and 20% above the computed value.
Type: long Default: 30000 (30 seconds) Valid Values: Importance: medium socket.connection.setup.timeout.ms
The amount of time the client will wait for the socket connection to be established. If the connection is not built before the timeout elapses, clients will close the socket channel. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the
socket.connection.setup.timeout.max.msvalue.Type: long Default: 10000 (10 seconds) Valid Values: Importance: medium ssl.enabled.protocols
The list of protocols enabled for SSL connections. The default is 'TLSv1.2,TLSv1.3'. This means that clients and servers will prefer TLSv1.3 if both support it and fallback to TLSv1.2 otherwise (assuming both support at least TLSv1.2). This default should be fine for most use cases. Also see the config documentation for `ssl.protocol` to understand how it can impact the TLS version negotiation behavior.
Type: list Default: TLSv1.2,TLSv1.3 Valid Values: Importance: medium ssl.keystore.type
The file format of the key store file. This is optional for client. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium ssl.protocol
The SSL protocol used to generate the SSLContext. The default is 'TLSv1.3', which should be fine for most use cases. A typical alternative to the default is 'TLSv1.2'. Allowed values for this config are dependent on the JVM. Clients using the defaults for this config and 'ssl.enabled.protocols' will downgrade to 'TLSv1.2' if the server does not support 'TLSv1.3'. If this config is set to 'TLSv1.2', however, clients will not use 'TLSv1.3' even if it is one of the values in `ssl.enabled.protocols` and the server only supports 'TLSv1.3'.
Type: string Default: TLSv1.3 Valid Values: Importance: medium ssl.provider
The name of the security provider used for SSL connections. Default value is the default security provider of the JVM.
Type: string Default: null Valid Values: Importance: medium ssl.truststore.type
The file format of the trust store file. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium auto.commit.interval.ms
The frequency in milliseconds that the consumer offsets are auto-committed to Kafka if
enable.auto.commitis set totrue.Type: int Default: 5000 (5 seconds) Valid Values: [0,...] Importance: low check.crcs
Automatically check the CRC32 of the records consumed. This ensures no on-the-wire or on-disk corruption to the messages occurred. This check adds some overhead, so it may be disabled in cases seeking extreme performance.
Type: boolean Default: true Valid Values: Importance: low client.id
An id string to pass to the server when making requests. The purpose of this is to be able to track the source of requests beyond just ip/port by allowing a logical application name to be included in server-side request logging.
Type: string Default: "" Valid Values: Importance: low client.rack
A rack identifier for this client. This can be any string value which indicates where this client is physically located. It corresponds with the broker config 'broker.rack'
Type: string Default: "" Valid Values: Importance: low enable.metrics.push
Whether to enable pushing of client metrics to the cluster, if the cluster has a client metrics subscription which matches this client.
Type: boolean Default: true Valid Values: Importance: low fetch.max.wait.ms
The maximum amount of time the server will block before answering the fetch request there isn't sufficient data to immediately satisfy the requirement given by fetch.min.bytes. This config is used only for local log fetch. To tune the remote fetch maximum wait time, please refer to 'remote.fetch.max.wait.ms' broker config
Type: int Default: 500 Valid Values: [0,...] Importance: low interceptor.classes
A list of classes to use as interceptors. Implementing the
org.apache.kafka.clients.consumer.ConsumerInterceptorinterface allows you to intercept (and possibly mutate) records received by the consumer. By default, there are no interceptors.Type: list Default: "" Valid Values: non-null string Importance: low metadata.max.age.ms
The period of time in milliseconds after which we force a refresh of metadata even if we haven't seen any partition leadership changes to proactively discover any new brokers or partitions.
Type: long Default: 300000 (5 minutes) Valid Values: [0,...] Importance: low metadata.recovery.rebootstrap.trigger.ms
If a client configured to rebootstrap using
metadata.recovery.strategy=rebootstrapis unable to obtain metadata from any of the brokers in the last known metadata for this interval, client repeats the bootstrap process usingbootstrap.serversconfiguration.Type: long Default: 300000 (5 minutes) Valid Values: [0,...] Importance: low metadata.recovery.strategy
Controls how the client recovers when none of the brokers known to it is available. If set to
none, the client fails. If set torebootstrap, the client repeats the bootstrap process usingbootstrap.servers. Rebootstrapping is useful when a client communicates with brokers so infrequently that the set of brokers may change entirely before the client refreshes metadata. Metadata recovery is triggered when all last-known brokers appear unavailable simultaneously. Brokers appear unavailable when disconnected and no current retry attempt is in-progress. Consider increasingreconnect.backoff.msandreconnect.backoff.max.msand decreasingsocket.connection.setup.timeout.msandsocket.connection.setup.timeout.max.msfor the client. Rebootstrap is also triggered if connection cannot be established to any of the brokers formetadata.recovery.rebootstrap.trigger.msmilliseconds or if server requests rebootstrap.Type: string Default: rebootstrap Valid Values: (case insensitive) [REBOOTSTRAP, NONE] Importance: low metric.reporters
A list of classes to use as metrics reporters. Implementing the
org.apache.kafka.common.metrics.MetricsReporterinterface allows plugging in classes that will be notified of new metric creation.Type: list Default: org.apache.kafka.common.metrics.JmxReporter Valid Values: non-null string Importance: low metrics.num.samples
The number of samples maintained to compute metrics.
Type: int Default: 2 Valid Values: [1,...] Importance: low metrics.recording.level
The highest recording level for metrics. It has three levels for recording metrics - info, debug, and trace.
INFO level records only essential metrics necessary for monitoring system performance and health. It collects vital data without gathering too much detail, making it suitable for production environments where minimal overhead is desired.
DEBUG level records most metrics, providing more detailed information about the system's operation. It's useful for development and testing environments where you need deeper insights to debug and fine-tune the application.
TRACE level records all possible metrics, capturing every detail about the system's performance and operation. It's best for controlled environments where in-depth analysis is required, though it can introduce significant overhead.Type: string Default: INFO Valid Values: [INFO, DEBUG, TRACE] Importance: low metrics.sample.window.ms
The window of time a metrics sample is computed over.
Type: long Default: 30000 (30 seconds) Valid Values: [0,...] Importance: low reconnect.backoff.max.ms
The maximum amount of time in milliseconds to wait when reconnecting to a broker that has repeatedly failed to connect. If provided, the backoff per host will increase exponentially for each consecutive connection failure, up to this maximum. After calculating the backoff increase, 20% random jitter is added to avoid connection storms.
Type: long Default: 1000 (1 second) Valid Values: [0,...] Importance: low reconnect.backoff.ms
The base amount of time to wait before attempting to reconnect to a given host. This avoids repeatedly connecting to a host in a tight loop. This backoff applies to all connection attempts by the client to a broker. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the
reconnect.backoff.max.msvalue.Type: long Default: 50 Valid Values: [0,...] Importance: low retry.backoff.max.ms
The maximum amount of time in milliseconds to wait when retrying a request to the broker that has repeatedly failed. If provided, the backoff per client will increase exponentially for each failed request, up to this maximum. To prevent all clients from being synchronized upon retry, a randomized jitter with a factor of 0.2 will be applied to the backoff, resulting in the backoff falling within a range between 20% below and 20% above the computed value. If
retry.backoff.msis set to be higher thanretry.backoff.max.ms, thenretry.backoff.max.mswill be used as a constant backoff from the beginning without any exponential increaseType: long Default: 1000 (1 second) Valid Values: [0,...] Importance: low retry.backoff.ms
The amount of time to wait before attempting to retry a failed request to a given topic partition. This avoids repeatedly sending requests in a tight loop under some failure scenarios. This value is the initial backoff value and will increase exponentially for each failed request, up to the
retry.backoff.max.msvalue.Type: long Default: 100 Valid Values: [0,...] Importance: low sasl.kerberos.kinit.cmd
Kerberos kinit command path.
Type: string Default: /usr/bin/kinit Valid Values: Importance: low sasl.kerberos.min.time.before.relogin
Login thread sleep time between refresh attempts.
Type: long Default: 60000 Valid Values: Importance: low sasl.kerberos.ticket.renew.jitter
Percentage of random jitter added to the renewal time.
Type: double Default: 0.05 Valid Values: Importance: low sasl.kerberos.ticket.renew.window.factor
Login thread will sleep until the specified window factor of time from last refresh to ticket's expiry has been reached, at which time it will try to renew the ticket.
Type: double Default: 0.8 Valid Values: Importance: low sasl.login.connect.timeout.ms
The (optional) value in milliseconds for the external authentication provider connection timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low sasl.login.read.timeout.ms
The (optional) value in milliseconds for the external authentication provider read timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low sasl.login.refresh.buffer.seconds
The amount of buffer time before credential expiration to maintain when refreshing a credential, in seconds. If a refresh would otherwise occur closer to expiration than the number of buffer seconds then the refresh will be moved up to maintain as much of the buffer time as possible. Legal values are between 0 and 3600 (1 hour); a default value of 300 (5 minutes) is used if no value is specified. This value and sasl.login.refresh.min.period.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 300 Valid Values: [0,...,3600] Importance: low sasl.login.refresh.min.period.seconds
The desired minimum time for the login refresh thread to wait before refreshing a credential, in seconds. Legal values are between 0 and 900 (15 minutes); a default value of 60 (1 minute) is used if no value is specified. This value and sasl.login.refresh.buffer.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 60 Valid Values: [0,...,900] Importance: low sasl.login.refresh.window.factor
Login refresh thread will sleep until the specified window factor relative to the credential's lifetime has been reached, at which time it will try to refresh the credential. Legal values are between 0.5 (50%) and 1.0 (100%) inclusive; a default value of 0.8 (80%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.8 Valid Values: [0.5,...,1.0] Importance: low sasl.login.refresh.window.jitter
The maximum amount of random jitter relative to the credential's lifetime that is added to the login refresh thread's sleep time. Legal values are between 0 and 0.25 (25%) inclusive; a default value of 0.05 (5%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.05 Valid Values: [0.0,...,0.25] Importance: low sasl.login.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low sasl.login.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 100 Valid Values: Importance: low sasl.oauthbearer.clock.skew.seconds
The (optional) value in seconds to allow for differences between the time of the OAuth/OIDC identity provider and the broker.
Type: int Default: 30 Valid Values: Importance: low sasl.oauthbearer.expected.audience
The (optional) comma-delimited setting for the broker to use to verify that the JWT was issued for one of the expected audiences. The JWT will be inspected for the standard OAuth "aud" claim and if this value is set, the broker will match the value from JWT's "aud" claim to see if there is an exact match. If there is no match, the broker will reject the JWT and authentication will fail.
Type: list Default: null Valid Values: Importance: low sasl.oauthbearer.expected.issuer
The (optional) setting for the broker to use to verify that the JWT was created by the expected issuer. The JWT will be inspected for the standard OAuth "iss" claim and if this value is set, the broker will match it exactly against what is in the JWT's "iss" claim. If there is no match, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: low sasl.oauthbearer.header.urlencode
The (optional) setting to enable the OAuth client to URL-encode the client_id and client_secret in the authorization header in accordance with RFC6749, see here for more details. The default value is set to 'false' for backward compatibility
Type: boolean Default: false Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.refresh.ms
The (optional) value in milliseconds for the broker to wait between refreshing its JWKS (JSON Web Key Set) cache that contains the keys to verify the signature of the JWT.
Type: long Default: 3600000 (1 hour) Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between attempts to retrieve the JWKS (JSON Web Key Set) from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between JWKS (JSON Web Key Set) retrieval attempts from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 100 Valid Values: Importance: low sasl.oauthbearer.scope.claim.name
The OAuth claim for the scope is often named "scope", but this (optional) setting can provide a different name to use for the scope included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: scope Valid Values: Importance: low sasl.oauthbearer.sub.claim.name
The OAuth claim for the subject is often named "sub", but this (optional) setting can provide a different name to use for the subject included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: sub Valid Values: Importance: low security.providers
A list of configurable creator classes each returning a provider implementing security algorithms. These classes should implement the
org.apache.kafka.common.security.auth.SecurityProviderCreatorinterface.Type: string Default: null Valid Values: Importance: low ssl.cipher.suites
A list of cipher suites. This is a named combination of authentication, encryption, MAC and key exchange algorithm used to negotiate the security settings for a network connection using TLS or SSL network protocol. By default all the available cipher suites are supported.
Type: list Default: null Valid Values: Importance: low ssl.endpoint.identification.algorithm
The endpoint identification algorithm to validate server hostname using server certificate.
Type: string Default: https Valid Values: Importance: low ssl.engine.factory.class
The class of type org.apache.kafka.common.security.auth.SslEngineFactory to provide SSLEngine objects. Default value is org.apache.kafka.common.security.ssl.DefaultSslEngineFactory. Alternatively, setting this to org.apache.kafka.common.security.ssl.CommonNameLoggingSslEngineFactory will log the common name of expired SSL certificates used by clients to authenticate at any of the brokers with log level INFO. Note that this will cause a tiny delay during establishment of new connections from mTLS clients to brokers due to the extra code for examining the certificate chain provided by the client. Note further that the implementation uses a custom truststore based on the standard Java truststore and thus might be considered a security risk due to not being as mature as the standard one.
Type: class Default: null Valid Values: Importance: low ssl.keymanager.algorithm
The algorithm used by key manager factory for SSL connections. Default value is the key manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: SunX509 Valid Values: Importance: low ssl.secure.random.implementation
The SecureRandom PRNG implementation to use for SSL cryptography operations.
Type: string Default: null Valid Values: Importance: low ssl.trustmanager.algorithm
The algorithm used by trust manager factory for SSL connections. Default value is the trust manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: PKIX Valid Values: Importance: low
Kafka Connect Configs
Below is the configuration of the Kafka Connect framework.
config.storage.topic
The name of the Kafka topic where connector configurations are stored
Type: string Default: Valid Values: Importance: high group.id
A unique string that identifies the Connect cluster group this worker belongs to.
Type: string Default: Valid Values: Importance: high key.converter
Converter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the keys in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro.
Type: class Default: Valid Values: Importance: high offset.storage.topic
The name of the Kafka topic where source connector offsets are stored
Type: string Default: Valid Values: Importance: high status.storage.topic
The name of the Kafka topic where connector and task status are stored
Type: string Default: Valid Values: Importance: high value.converter
Converter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the values in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro.
Type: class Default: Valid Values: Importance: high bootstrap.servers
A list of host/port pairs used to establish the initial connection to the Kafka cluster. Clients use this list to bootstrap and discover the full set of Kafka brokers. While the order of servers in the list does not matter, we recommend including more than one server to ensure resilience if any servers are down. This list does not need to contain the entire set of brokers, as Kafka clients automatically manage and update connections to the cluster efficiently. This list must be in the form
host1:port1,host2:port2,....Type: list Default: localhost:9092 Valid Values: Importance: high exactly.once.source.support
Whether to enable exactly-once support for source connectors in the cluster by using transactions to write source records and their source offsets, and by proactively fencing out old task generations before bringing up new ones.
To enable exactly-once source support on a new cluster, set this property to 'enabled'. To enable support on an existing cluster, first set to 'preparing' on every worker in the cluster, then set to 'enabled'. A rolling upgrade may be used for both changes. For more information on this feature, see the exactly-once source support documentation.Type: string Default: disabled Valid Values: (case insensitive) [DISABLED, ENABLED, PREPARING] Importance: high heartbeat.interval.ms
The expected time between heartbeats to the group coordinator when using Kafka's group management facilities. Heartbeats are used to ensure that the worker's session stays active and to facilitate rebalancing when new members join or leave the group. The value must be set lower than
session.timeout.ms, but typically should be set no higher than 1/3 of that value. It can be adjusted even lower to control the expected time for normal rebalances.Type: int Default: 3000 (3 seconds) Valid Values: Importance: high rebalance.timeout.ms
The maximum allowed time for each worker to join the group once a rebalance has begun. This is basically a limit on the amount of time needed for all tasks to flush any pending data and commit offsets. If the timeout is exceeded, then the worker will be removed from the group, which will cause offset commit failures.
Type: int Default: 60000 (1 minute) Valid Values: Importance: high session.timeout.ms
The timeout used to detect worker failures. The worker sends periodic heartbeats to indicate its liveness to the broker. If no heartbeats are received by the broker before the expiration of this session timeout, then the broker will remove the worker from the group and initiate a rebalance. Note that the value must be in the allowable range as configured in the broker configuration by
group.min.session.timeout.msandgroup.max.session.timeout.ms.Type: int Default: 10000 (10 seconds) Valid Values: Importance: high ssl.key.password
The password of the private key in the key store file or the PEM key specified in 'ssl.keystore.key'.
Type: password Default: null Valid Values: Importance: high ssl.keystore.certificate.chain
Certificate chain in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with a list of X.509 certificates
Type: password Default: null Valid Values: Importance: high ssl.keystore.key
Private key in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with PKCS#8 keys. If the key is encrypted, key password must be specified using 'ssl.key.password'
Type: password Default: null Valid Values: Importance: high ssl.keystore.location
The location of the key store file. This is optional for client and can be used for two-way authentication for client.
Type: string Default: null Valid Values: Importance: high ssl.keystore.password
The store password for the key store file. This is optional for client and only needed if 'ssl.keystore.location' is configured. Key store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: high ssl.truststore.certificates
Trusted certificates in the format specified by 'ssl.truststore.type'. Default SSL engine factory supports only PEM format with X.509 certificates.
Type: password Default: null Valid Values: Importance: high ssl.truststore.location
The location of the trust store file.
Type: string Default: null Valid Values: Importance: high ssl.truststore.password
The password for the trust store file. If a password is not set, trust store file configured will still be used, but integrity checking is disabled. Trust store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: high client.dns.lookup
Controls how the client uses DNS lookups. If set to
use_all_dns_ips, connect to each returned IP address in sequence until a successful connection is established. After a disconnection, the next IP is used. Once all IPs have been used once, the client resolves the IP(s) from the hostname again (both the JVM and the OS cache DNS name lookups, however). If set toresolve_canonical_bootstrap_servers_only, resolve each bootstrap address into a list of canonical names. After the bootstrap phase, this behaves the same asuse_all_dns_ips.Type: string Default: use_all_dns_ips Valid Values: [use_all_dns_ips, resolve_canonical_bootstrap_servers_only] Importance: medium connections.max.idle.ms
Close idle connections after the number of milliseconds specified by this config.
Type: long Default: 540000 (9 minutes) Valid Values: Importance: medium connector.client.config.override.policy
Class name or alias of implementation of
ConnectorClientConfigOverridePolicy. Defines what client configurations can be overridden by the connector. The default implementation is `All`, meaning connector configurations can override all client properties. The other possible policies in the framework include `None` to disallow connectors from overriding client properties, and `Principal` to allow connectors to override only client principals.Type: string Default: All Valid Values: Importance: medium receive.buffer.bytes
The size of the TCP receive buffer (SO_RCVBUF) to use when reading data. If the value is -1, the OS default will be used.
Type: int Default: 32768 (32 kibibytes) Valid Values: [-1,...] Importance: medium request.timeout.ms
The configuration controls the maximum amount of time the client will wait for the response of a request. If the response is not received before the timeout elapses the client will resend the request if necessary or fail the request if retries are exhausted.
Type: int Default: 40000 (40 seconds) Valid Values: [0,...] Importance: medium sasl.client.callback.handler.class
The fully qualified name of a SASL client callback handler class that implements the AuthenticateCallbackHandler interface.
Type: class Default: null Valid Values: Importance: medium sasl.jaas.config
JAAS login context parameters for SASL connections in the format used by JAAS configuration files. JAAS configuration file format is described here. The format for the value is:
loginModuleClass controlFlag (optionName=optionValue)*;. For brokers, the config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.jaas.config=com.example.ScramLoginModule required;Type: password Default: null Valid Values: Importance: medium sasl.kerberos.service.name
The Kerberos principal name that Kafka runs as. This can be defined either in Kafka's JAAS config or in Kafka's config.
Type: string Default: null Valid Values: Importance: medium sasl.login.callback.handler.class
The fully qualified name of a SASL login callback handler class that implements the AuthenticateCallbackHandler interface. For brokers, login callback handler config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.callback.handler.class=com.example.CustomScramLoginCallbackHandler
Type: class Default: null Valid Values: Importance: medium sasl.login.class
The fully qualified name of a class that implements the Login interface. For brokers, login config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.class=com.example.CustomScramLogin
Type: class Default: null Valid Values: Importance: medium sasl.mechanism
SASL mechanism used for client connections. This may be any mechanism for which a security provider is available. GSSAPI is the default mechanism.
Type: string Default: GSSAPI Valid Values: Importance: medium sasl.oauthbearer.jwks.endpoint.url
The OAuth/OIDC provider URL from which the provider's JWKS (JSON Web Key Set) can be retrieved. The URL can be HTTP(S)-based or file-based. If the URL is HTTP(S)-based, the JWKS data will be retrieved from the OAuth/OIDC provider via the configured URL on broker startup. All then-current keys will be cached on the broker for incoming requests. If an authentication request is received for a JWT that includes a "kid" header claim value that isn't yet in the cache, the JWKS endpoint will be queried again on demand. However, the broker polls the URL every sasl.oauthbearer.jwks.endpoint.refresh.ms milliseconds to refresh the cache with any forthcoming keys before any JWT requests that include them are received. If the URL is file-based, the broker will load the JWKS file from a configured location on startup. In the event that the JWT includes a "kid" header value that isn't in the JWKS file, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: medium sasl.oauthbearer.token.endpoint.url
The URL for the OAuth/OIDC identity provider. If the URL is HTTP(S)-based, it is the issuer's token endpoint URL to which requests will be made to login based on the configuration in sasl.jaas.config. If the URL is file-based, it specifies a file containing an access token (in JWT serialized form) issued by the OAuth/OIDC identity provider to use for authorization.
Type: string Default: null Valid Values: Importance: medium security.protocol
Protocol used to communicate with brokers.
Type: string Default: PLAINTEXT Valid Values: (case insensitive) [SASL_SSL, PLAINTEXT, SSL, SASL_PLAINTEXT] Importance: medium send.buffer.bytes
The size of the TCP send buffer (SO_SNDBUF) to use when sending data. If the value is -1, the OS default will be used.
Type: int Default: 131072 (128 kibibytes) Valid Values: [-1,...] Importance: medium ssl.enabled.protocols
The list of protocols enabled for SSL connections. The default is 'TLSv1.2,TLSv1.3'. This means that clients and servers will prefer TLSv1.3 if both support it and fallback to TLSv1.2 otherwise (assuming both support at least TLSv1.2). This default should be fine for most use cases. Also see the config documentation for `ssl.protocol` to understand how it can impact the TLS version negotiation behavior.
Type: list Default: TLSv1.2,TLSv1.3 Valid Values: Importance: medium ssl.keystore.type
The file format of the key store file. This is optional for client. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium ssl.protocol
The SSL protocol used to generate the SSLContext. The default is 'TLSv1.3', which should be fine for most use cases. A typical alternative to the default is 'TLSv1.2'. Allowed values for this config are dependent on the JVM. Clients using the defaults for this config and 'ssl.enabled.protocols' will downgrade to 'TLSv1.2' if the server does not support 'TLSv1.3'. If this config is set to 'TLSv1.2', however, clients will not use 'TLSv1.3' even if it is one of the values in `ssl.enabled.protocols` and the server only supports 'TLSv1.3'.
Type: string Default: TLSv1.3 Valid Values: Importance: medium ssl.provider
The name of the security provider used for SSL connections. Default value is the default security provider of the JVM.
Type: string Default: null Valid Values: Importance: medium ssl.truststore.type
The file format of the trust store file. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium worker.sync.timeout.ms
When the worker is out of sync with other workers and needs to resynchronize configurations, wait up to this amount of time before giving up, leaving the group, and waiting a backoff period before rejoining.
Type: int Default: 3000 (3 seconds) Valid Values: Importance: medium worker.unsync.backoff.ms
When the worker is out of sync with other workers and fails to catch up within worker.sync.timeout.ms, leave the Connect cluster for this long before rejoining.
Type: int Default: 300000 (5 minutes) Valid Values: Importance: medium access.control.allow.methods
Sets the methods supported for cross origin requests by setting the Access-Control-Allow-Methods header. The default value of the Access-Control-Allow-Methods header allows cross origin requests for GET, POST and HEAD.
Type: string Default: "" Valid Values: Importance: low access.control.allow.origin
Value to set the Access-Control-Allow-Origin header to for REST API requests.To enable cross origin access, set this to the domain of the application that should be permitted to access the API, or '*' to allow access from any domain. The default value only allows access from the domain of the REST API.
Type: string Default: "" Valid Values: Importance: low admin.listeners
List of comma-separated URIs the Admin REST API will listen on. The supported protocols are HTTP and HTTPS. An empty or blank string will disable this feature. The default behavior is to use the regular listener (specified by the 'listeners' property).
Type: list Default: null Valid Values: List of comma-separated URLs, ex: http://localhost:8080,https://localhost:8443. Importance: low client.id
An id string to pass to the server when making requests. The purpose of this is to be able to track the source of requests beyond just ip/port by allowing a logical application name to be included in server-side request logging.
Type: string Default: "" Valid Values: Importance: low config.providers
Comma-separated names of
ConfigProviderclasses, loaded and used in the order specified. Implementing the interfaceConfigProviderallows you to replace variable references in connector configurations, such as for externalized secrets.Type: list Default: "" Valid Values: Importance: low config.storage.replication.factor
Replication factor used when creating the configuration storage topic
Type: short Default: 3 Valid Values: Positive number not larger than the number of brokers in the Kafka cluster, or -1 to use the broker's default Importance: low connect.protocol
Compatibility mode for Kafka Connect Protocol
Type: string Default: sessioned Valid Values: [eager, compatible, sessioned] Importance: low header.converter
HeaderConverter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the header values in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro. By default, the SimpleHeaderConverter is used to serialize header values to strings and deserialize them by inferring the schemas.
Type: class Default: org.apache.kafka.connect.storage.SimpleHeaderConverter Valid Values: Importance: low inter.worker.key.generation.algorithm
The algorithm to use for generating internal request keys. The algorithm 'HmacSHA256' will be used as a default on JVMs that support it; on other JVMs, no default is used and a value for this property must be manually specified in the worker config.
Type: string Default: HmacSHA256 Valid Values: Any KeyGenerator algorithm supported by the worker JVM Importance: low inter.worker.key.size
The size of the key to use for signing internal requests, in bits. If null, the default key size for the key generation algorithm will be used.
Type: int Default: null Valid Values: Importance: low inter.worker.key.ttl.ms
The TTL of generated session keys used for internal request validation (in milliseconds)
Type: int Default: 3600000 (1 hour) Valid Values: [0,...,2147483647] Importance: low inter.worker.signature.algorithm
The algorithm used to sign internal requestsThe algorithm 'inter.worker.signature.algorithm' will be used as a default on JVMs that support it; on other JVMs, no default is used and a value for this property must be manually specified in the worker config.
Type: string Default: HmacSHA256 Valid Values: Any MAC algorithm supported by the worker JVM Importance: low inter.worker.verification.algorithms
A list of permitted algorithms for verifying internal requests, which must include the algorithm used for the inter.worker.signature.algorithm property. The algorithm(s) '[HmacSHA256]' will be used as a default on JVMs that provide them; on other JVMs, no default is used and a value for this property must be manually specified in the worker config.
Type: list Default: HmacSHA256 Valid Values: A list of one or more MAC algorithms, each supported by the worker JVM Importance: low listeners
List of comma-separated URIs the REST API will listen on. The supported protocols are HTTP and HTTPS.
Specify hostname as 0.0.0.0 to bind to all interfaces.
Leave hostname empty to bind to default interface.
Examples of legal listener lists: HTTP://myhost:8083,HTTPS://myhost:8084Type: list Default: http://:8083 Valid Values: List of comma-separated URLs, ex: http://localhost:8080,https://localhost:8443. Importance: low metadata.max.age.ms
The period of time in milliseconds after which we force a refresh of metadata even if we haven't seen any partition leadership changes to proactively discover any new brokers or partitions.
Type: long Default: 300000 (5 minutes) Valid Values: [0,...] Importance: low metadata.recovery.rebootstrap.trigger.ms
If a client configured to rebootstrap using
metadata.recovery.strategy=rebootstrapis unable to obtain metadata from any of the brokers in the last known metadata for this interval, client repeats the bootstrap process usingbootstrap.serversconfiguration.Type: long Default: 300000 (5 minutes) Valid Values: [0,...] Importance: low metadata.recovery.strategy
Controls how the client recovers when none of the brokers known to it is available. If set to
none, the client fails. If set torebootstrap, the client repeats the bootstrap process usingbootstrap.servers. Rebootstrapping is useful when a client communicates with brokers so infrequently that the set of brokers may change entirely before the client refreshes metadata. Metadata recovery is triggered when all last-known brokers appear unavailable simultaneously. Brokers appear unavailable when disconnected and no current retry attempt is in-progress. Consider increasingreconnect.backoff.msandreconnect.backoff.max.msand decreasingsocket.connection.setup.timeout.msandsocket.connection.setup.timeout.max.msfor the client. Rebootstrap is also triggered if connection cannot be established to any of the brokers formetadata.recovery.rebootstrap.trigger.msmilliseconds or if server requests rebootstrap.Type: string Default: rebootstrap Valid Values: (case insensitive) [REBOOTSTRAP, NONE] Importance: low metric.reporters
A list of classes to use as metrics reporters. Implementing the
org.apache.kafka.common.metrics.MetricsReporterinterface allows plugging in classes that will be notified of new metric creation.Type: list Default: org.apache.kafka.common.metrics.JmxReporter Valid Values: Importance: low metrics.num.samples
The number of samples maintained to compute metrics.
Type: int Default: 2 Valid Values: [1,...] Importance: low metrics.recording.level
The highest recording level for metrics. It has three levels for recording metrics - info, debug, and trace.
INFO level records only essential metrics necessary for monitoring system performance and health. It collects vital data without gathering too much detail, making it suitable for production environments where minimal overhead is desired.
DEBUG level records most metrics, providing more detailed information about the system's operation. It's useful for development and testing environments where you need deeper insights to debug and fine-tune the application.
TRACE level records all possible metrics, capturing every detail about the system's performance and operation. It's best for controlled environments where in-depth analysis is required, though it can introduce significant overhead.Type: string Default: INFO Valid Values: [INFO, DEBUG] Importance: low metrics.sample.window.ms
The window of time a metrics sample is computed over.
Type: long Default: 30000 (30 seconds) Valid Values: [0,...] Importance: low offset.flush.interval.ms
Interval at which to try committing offsets for tasks.
Type: long Default: 60000 (1 minute) Valid Values: Importance: low offset.flush.timeout.ms
Maximum number of milliseconds to wait for records to flush and partition offset data to be committed to offset storage before cancelling the process and restoring the offset data to be committed in a future attempt. This property has no effect for source connectors running with exactly-once support.
Type: long Default: 5000 (5 seconds) Valid Values: Importance: low offset.storage.partitions
The number of partitions used when creating the offset storage topic
Type: int Default: 25 Valid Values: Positive number, or -1 to use the broker's default Importance: low offset.storage.replication.factor
Replication factor used when creating the offset storage topic
Type: short Default: 3 Valid Values: Positive number not larger than the number of brokers in the Kafka cluster, or -1 to use the broker's default Importance: low plugin.discovery
Method to use to discover plugins present in the classpath and plugin.path configuration. This can be one of multiple values with the following meanings:
* only_scan: Discover plugins only by reflection. Plugins which are not discoverable by ServiceLoader will not impact worker startup.
* hybrid_warn: Discover plugins reflectively and by ServiceLoader. Plugins which are not discoverable by ServiceLoader will print warnings during worker startup.
* hybrid_fail: Discover plugins reflectively and by ServiceLoader. Plugins which are not discoverable by ServiceLoader will cause worker startup to fail.
* service_load: Discover plugins only by ServiceLoader. Faster startup than other modes. Plugins which are not discoverable by ServiceLoader may not be usable.Type: string Default: hybrid_warn Valid Values: (case insensitive) [ONLY_SCAN, SERVICE_LOAD, HYBRID_WARN, HYBRID_FAIL] Importance: low plugin.path
List of paths separated by commas (,) that contain plugins (connectors, converters, transformations). The list should consist of top level directories that include any combination of:
a) directories immediately containing jars with plugins and their dependencies
b) uber-jars with plugins and their dependencies
c) directories immediately containing the package directory structure of classes of plugins and their dependencies
Note: symlinks will be followed to discover dependencies or plugins.
Examples: plugin.path=/usr/local/share/java,/usr/local/share/kafka/plugins,/opt/connectors
Do not use config provider variables in this property, since the raw path is used by the worker's scanner before config providers are initialized and used to replace variables.Type: list Default: null Valid Values: Importance: low reconnect.backoff.max.ms
The maximum amount of time in milliseconds to wait when reconnecting to a broker that has repeatedly failed to connect. If provided, the backoff per host will increase exponentially for each consecutive connection failure, up to this maximum. After calculating the backoff increase, 20% random jitter is added to avoid connection storms.
Type: long Default: 1000 (1 second) Valid Values: [0,...] Importance: low reconnect.backoff.ms
The base amount of time to wait before attempting to reconnect to a given host. This avoids repeatedly connecting to a host in a tight loop. This backoff applies to all connection attempts by the client to a broker. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the
reconnect.backoff.max.msvalue.Type: long Default: 50 Valid Values: [0,...] Importance: low response.http.headers.config
Rules for REST API HTTP response headers
Type: string Default: "" Valid Values: Comma-separated header rules, where each header rule is of the form '[action] [header name]:[header value]' and optionally surrounded by double quotes if any part of a header rule contains a comma Importance: low rest.advertised.host.name
If this is set, this is the hostname that will be given out to other workers to connect to.
Type: string Default: null Valid Values: Importance: low rest.advertised.listener
Sets the advertised listener (HTTP or HTTPS) which will be given to other workers to use.
Type: string Default: null Valid Values: Importance: low rest.advertised.port
If this is set, this is the port that will be given out to other workers to connect to.
Type: int Default: null Valid Values: Importance: low rest.extension.classes
Comma-separated names of
ConnectRestExtensionclasses, loaded and called in the order specified. Implementing the interfaceConnectRestExtensionallows you to inject into Connect's REST API user defined resources like filters. Typically used to add custom capability like logging, security, etc.Type: list Default: "" Valid Values: Importance: low retry.backoff.max.ms
The maximum amount of time in milliseconds to wait when retrying a request to the broker that has repeatedly failed. If provided, the backoff per client will increase exponentially for each failed request, up to this maximum. To prevent all clients from being synchronized upon retry, a randomized jitter with a factor of 0.2 will be applied to the backoff, resulting in the backoff falling within a range between 20% below and 20% above the computed value. If
retry.backoff.msis set to be higher thanretry.backoff.max.ms, thenretry.backoff.max.mswill be used as a constant backoff from the beginning without any exponential increaseType: long Default: 1000 (1 second) Valid Values: [0,...] Importance: low retry.backoff.ms
The amount of time to wait before attempting to retry a failed request to a given topic partition. This avoids repeatedly sending requests in a tight loop under some failure scenarios. This value is the initial backoff value and will increase exponentially for each failed request, up to the
retry.backoff.max.msvalue.Type: long Default: 100 Valid Values: [0,...] Importance: low sasl.kerberos.kinit.cmd
Kerberos kinit command path.
Type: string Default: /usr/bin/kinit Valid Values: Importance: low sasl.kerberos.min.time.before.relogin
Login thread sleep time between refresh attempts.
Type: long Default: 60000 Valid Values: Importance: low sasl.kerberos.ticket.renew.jitter
Percentage of random jitter added to the renewal time.
Type: double Default: 0.05 Valid Values: Importance: low sasl.kerberos.ticket.renew.window.factor
Login thread will sleep until the specified window factor of time from last refresh to ticket's expiry has been reached, at which time it will try to renew the ticket.
Type: double Default: 0.8 Valid Values: Importance: low sasl.login.connect.timeout.ms
The (optional) value in milliseconds for the external authentication provider connection timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low sasl.login.read.timeout.ms
The (optional) value in milliseconds for the external authentication provider read timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low sasl.login.refresh.buffer.seconds
The amount of buffer time before credential expiration to maintain when refreshing a credential, in seconds. If a refresh would otherwise occur closer to expiration than the number of buffer seconds then the refresh will be moved up to maintain as much of the buffer time as possible. Legal values are between 0 and 3600 (1 hour); a default value of 300 (5 minutes) is used if no value is specified. This value and sasl.login.refresh.min.period.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 300 Valid Values: [0,...,3600] Importance: low sasl.login.refresh.min.period.seconds
The desired minimum time for the login refresh thread to wait before refreshing a credential, in seconds. Legal values are between 0 and 900 (15 minutes); a default value of 60 (1 minute) is used if no value is specified. This value and sasl.login.refresh.buffer.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 60 Valid Values: [0,...,900] Importance: low sasl.login.refresh.window.factor
Login refresh thread will sleep until the specified window factor relative to the credential's lifetime has been reached, at which time it will try to refresh the credential. Legal values are between 0.5 (50%) and 1.0 (100%) inclusive; a default value of 0.8 (80%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.8 Valid Values: [0.5,...,1.0] Importance: low sasl.login.refresh.window.jitter
The maximum amount of random jitter relative to the credential's lifetime that is added to the login refresh thread's sleep time. Legal values are between 0 and 0.25 (25%) inclusive; a default value of 0.05 (5%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.05 Valid Values: [0.0,...,0.25] Importance: low sasl.login.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low sasl.login.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 100 Valid Values: Importance: low sasl.oauthbearer.clock.skew.seconds
The (optional) value in seconds to allow for differences between the time of the OAuth/OIDC identity provider and the broker.
Type: int Default: 30 Valid Values: Importance: low sasl.oauthbearer.expected.audience
The (optional) comma-delimited setting for the broker to use to verify that the JWT was issued for one of the expected audiences. The JWT will be inspected for the standard OAuth "aud" claim and if this value is set, the broker will match the value from JWT's "aud" claim to see if there is an exact match. If there is no match, the broker will reject the JWT and authentication will fail.
Type: list Default: null Valid Values: Importance: low sasl.oauthbearer.expected.issuer
The (optional) setting for the broker to use to verify that the JWT was created by the expected issuer. The JWT will be inspected for the standard OAuth "iss" claim and if this value is set, the broker will match it exactly against what is in the JWT's "iss" claim. If there is no match, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: low sasl.oauthbearer.header.urlencode
The (optional) setting to enable the OAuth client to URL-encode the client_id and client_secret in the authorization header in accordance with RFC6749, see here for more details. The default value is set to 'false' for backward compatibility
Type: boolean Default: false Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.refresh.ms
The (optional) value in milliseconds for the broker to wait between refreshing its JWKS (JSON Web Key Set) cache that contains the keys to verify the signature of the JWT.
Type: long Default: 3600000 (1 hour) Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between attempts to retrieve the JWKS (JSON Web Key Set) from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between JWKS (JSON Web Key Set) retrieval attempts from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 100 Valid Values: Importance: low sasl.oauthbearer.scope.claim.name
The OAuth claim for the scope is often named "scope", but this (optional) setting can provide a different name to use for the scope included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: scope Valid Values: Importance: low sasl.oauthbearer.sub.claim.name
The OAuth claim for the subject is often named "sub", but this (optional) setting can provide a different name to use for the subject included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: sub Valid Values: Importance: low scheduled.rebalance.max.delay.ms
The maximum delay that is scheduled in order to wait for the return of one or more departed workers before rebalancing and reassigning their connectors and tasks to the group. During this period the connectors and tasks of the departed workers remain unassigned
Type: int Default: 300000 (5 minutes) Valid Values: [0,...,2147483647] Importance: low socket.connection.setup.timeout.max.ms
The maximum amount of time the client will wait for the socket connection to be established. The connection setup timeout will increase exponentially for each consecutive connection failure up to this maximum. To avoid connection storms, a randomization factor of 0.2 will be applied to the timeout resulting in a random range between 20% below and 20% above the computed value.
Type: long Default: 30000 (30 seconds) Valid Values: [0,...] Importance: low socket.connection.setup.timeout.ms
The amount of time the client will wait for the socket connection to be established. If the connection is not built before the timeout elapses, clients will close the socket channel. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the
socket.connection.setup.timeout.max.msvalue.Type: long Default: 10000 (10 seconds) Valid Values: [0,...] Importance: low ssl.cipher.suites
A list of cipher suites. This is a named combination of authentication, encryption, MAC and key exchange algorithm used to negotiate the security settings for a network connection using TLS or SSL network protocol. By default all the available cipher suites are supported.
Type: list Default: null Valid Values: Importance: low ssl.client.auth
Configures kafka broker to request client authentication. The following settings are common:
ssl.client.auth=requiredIf set to required client authentication is required.ssl.client.auth=requestedThis means client authentication is optional. unlike required, if this option is set client can choose not to provide authentication information about itselfssl.client.auth=noneThis means client authentication is not needed.
Type: string Default: none Valid Values: [required, requested, none] Importance: low ssl.endpoint.identification.algorithm
The endpoint identification algorithm to validate server hostname using server certificate.
Type: string Default: https Valid Values: Importance: low ssl.engine.factory.class
The class of type org.apache.kafka.common.security.auth.SslEngineFactory to provide SSLEngine objects. Default value is org.apache.kafka.common.security.ssl.DefaultSslEngineFactory. Alternatively, setting this to org.apache.kafka.common.security.ssl.CommonNameLoggingSslEngineFactory will log the common name of expired SSL certificates used by clients to authenticate at any of the brokers with log level INFO. Note that this will cause a tiny delay during establishment of new connections from mTLS clients to brokers due to the extra code for examining the certificate chain provided by the client. Note further that the implementation uses a custom truststore based on the standard Java truststore and thus might be considered a security risk due to not being as mature as the standard one.
Type: class Default: null Valid Values: Importance: low ssl.keymanager.algorithm
The algorithm used by key manager factory for SSL connections. Default value is the key manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: SunX509 Valid Values: Importance: low ssl.secure.random.implementation
The SecureRandom PRNG implementation to use for SSL cryptography operations.
Type: string Default: null Valid Values: Importance: low ssl.trustmanager.algorithm
The algorithm used by trust manager factory for SSL connections. Default value is the trust manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: PKIX Valid Values: Importance: low status.storage.partitions
The number of partitions used when creating the status storage topic
Type: int Default: 5 Valid Values: Positive number, or -1 to use the broker's default Importance: low status.storage.replication.factor
Replication factor used when creating the status storage topic
Type: short Default: 3 Valid Values: Positive number not larger than the number of brokers in the Kafka cluster, or -1 to use the broker's default Importance: low task.shutdown.graceful.timeout.ms
Amount of time to wait for tasks to shutdown gracefully. This is the total amount of time, not per task. All task have shutdown triggered, then they are waited on sequentially.
Type: long Default: 5000 (5 seconds) Valid Values: Importance: low topic.creation.enable
Whether to allow automatic creation of topics used by source connectors, when source connectors are configured with `topic.creation.` properties. Each task will use an admin client to create its topics and will not depend on the Kafka brokers to create topics automatically.
Type: boolean Default: true Valid Values: Importance: low topic.tracking.allow.reset
If set to true, it allows user requests to reset the set of active topics per connector.
Type: boolean Default: true Valid Values: Importance: low topic.tracking.enable
Enable tracking the set of active topics per connector during runtime.
Type: boolean Default: true Valid Values: Importance: low
Source Connector Configs
Below is the configuration of a source connector.
name
Globally unique name to use for this connector.
Type: string Default: Valid Values: non-empty string without ISO control characters Importance: high connector.class
Name or alias of the class for this connector. Must be a subclass of org.apache.kafka.connect.connector.Connector. If the connector is org.apache.kafka.connect.file.FileStreamSinkConnector, you can either specify this full name, or use "FileStreamSink" or "FileStreamSinkConnector" to make the configuration a bit shorter
Type: string Default: Valid Values: Importance: high tasks.max
Maximum number of tasks to use for this connector.
Type: int Default: 1 Valid Values: [1,...] Importance: high tasks.max.enforce
(Deprecated) Whether to enforce that the tasks.max property is respected by the connector. By default, connectors that generate too many tasks will fail, and existing sets of tasks that exceed the tasks.max property will also be failed. If this property is set to false, then connectors will be allowed to generate more than the maximum number of tasks, and existing sets of tasks that exceed the tasks.max property will be allowed to run. This property is deprecated and will be removed in an upcoming major release.
Type: boolean Default: true Valid Values: Importance: low key.converter
Converter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the keys in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro.
Type: class Default: null Valid Values: A concrete subclass of org.apache.kafka.connect.storage.Converter, A class with a public, no-argument constructor Importance: low value.converter
Converter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the values in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro.
Type: class Default: null Valid Values: A concrete subclass of org.apache.kafka.connect.storage.Converter, A class with a public, no-argument constructor Importance: low header.converter
HeaderConverter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the header values in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro. By default, the SimpleHeaderConverter is used to serialize header values to strings and deserialize them by inferring the schemas.
Type: class Default: null Valid Values: A concrete subclass of org.apache.kafka.connect.storage.HeaderConverter, A class with a public, no-argument constructor Importance: low config.action.reload
The action that Connect should take on the connector when changes in external configuration providers result in a change in the connector's configuration properties. A value of 'none' indicates that Connect will do nothing. A value of 'restart' indicates that Connect should restart/reload the connector with the updated configuration properties.The restart may actually be scheduled in the future if the external configuration provider indicates that a configuration value will expire in the future.
Type: string Default: restart Valid Values: [none, restart] Importance: low transforms
Aliases for the transformations to be applied to records.
Type: list Default: "" Valid Values: non-null string, unique transformation aliases Importance: low predicates
Aliases for the predicates used by transformations.
Type: list Default: "" Valid Values: non-null string, unique predicate aliases Importance: low errors.retry.timeout
The maximum duration in milliseconds that a failed operation will be reattempted. The default is 0, which means no retries will be attempted. Use -1 for infinite retries.
Type: long Default: 0 Valid Values: Importance: medium errors.retry.delay.max.ms
The maximum duration in milliseconds between consecutive retry attempts. Jitter will be added to the delay once this limit is reached to prevent thundering herd issues.
Type: long Default: 60000 (1 minute) Valid Values: Importance: medium errors.tolerance
Behavior for tolerating errors during connector operation. 'none' is the default value and signals that any error will result in an immediate connector task failure; 'all' changes the behavior to skip over problematic records.
Type: string Default: none Valid Values: [none, all] Importance: medium errors.log.enable
If true, write each error and the details of the failed operation and problematic record to the Connect application log. This is 'false' by default, so that only errors that are not tolerated are reported.
Type: boolean Default: false Valid Values: Importance: medium errors.log.include.messages
Whether to include in the log the Connect record that resulted in a failure. For sink records, the topic, partition, offset, and timestamp will be logged. For source records, the key and value (and their schemas), all headers, and the timestamp, Kafka topic, Kafka partition, source partition, and source offset will be logged. This is 'false' by default, which will prevent record keys, values, and headers from being written to log files.
Type: boolean Default: false Valid Values: Importance: medium topic.creation.groups
Groups of configurations for topics created by source connectors
Type: list Default: "" Valid Values: non-null string, unique topic creation groups Importance: low exactly.once.support
Permitted values are requested, required. If set to "required", forces a preflight check for the connector to ensure that it can provide exactly-once semantics with the given configuration. Some connectors may be capable of providing exactly-once semantics but not signal to Connect that they support this; in that case, documentation for the connector should be consulted carefully before creating it, and the value for this property should be set to "requested". Additionally, if the value is set to "required" but the worker that performs preflight validation does not have exactly-once support enabled for source connectors, requests to create or validate the connector will fail.
Type: string Default: requested Valid Values: (case insensitive) [REQUIRED, REQUESTED] Importance: medium transaction.boundary
Permitted values are: poll, interval, connector. If set to 'poll', a new producer transaction will be started and committed for every batch of records that each task from this connector provides to Connect. If set to 'connector', relies on connector-defined transaction boundaries; note that not all connectors are capable of defining their own transaction boundaries, and in that case, attempts to instantiate a connector with this value will fail. Finally, if set to 'interval', commits transactions only after a user-defined time interval has passed.
Type: string Default: poll Valid Values: (case insensitive) [INTERVAL, POLL, CONNECTOR] Importance: medium transaction.boundary.interval.ms
If 'transaction.boundary' is set to 'interval', determines the interval for producer transaction commits by connector tasks. If unset, defaults to the value of the worker-level 'offset.flush.interval.ms' property. It has no effect if a different transaction.boundary is specified.
Type: long Default: null Valid Values: [0,...] Importance: low offsets.storage.topic
The name of a separate offsets topic to use for this connector. If empty or not specified, the worker’s global offsets topic name will be used. If specified, the offsets topic will be created if it does not already exist on the Kafka cluster targeted by this connector (which may be different from the one used for the worker's global offsets topic if the bootstrap.servers property of the connector's producer has been overridden from the worker's). Only applicable in distributed mode; in standalone mode, setting this property will have no effect.
Type: string Default: null Valid Values: non-empty string Importance: low
Sink Connector Configs
Below is the configuration of a sink connector.
name
Globally unique name to use for this connector.
Type: string Default: Valid Values: non-empty string without ISO control characters Importance: high connector.class
Name or alias of the class for this connector. Must be a subclass of org.apache.kafka.connect.connector.Connector. If the connector is org.apache.kafka.connect.file.FileStreamSinkConnector, you can either specify this full name, or use "FileStreamSink" or "FileStreamSinkConnector" to make the configuration a bit shorter
Type: string Default: Valid Values: Importance: high tasks.max
Maximum number of tasks to use for this connector.
Type: int Default: 1 Valid Values: [1,...] Importance: high topics
List of topics to consume, separated by commas
Type: list Default: "" Valid Values: Importance: high topics.regex
Regular expression giving topics to consume. Under the hood, the regex is compiled to a
java.util.regex.Pattern. Only one of topics or topics.regex should be specified.Type: string Default: "" Valid Values: valid regex Importance: high tasks.max.enforce
(Deprecated) Whether to enforce that the tasks.max property is respected by the connector. By default, connectors that generate too many tasks will fail, and existing sets of tasks that exceed the tasks.max property will also be failed. If this property is set to false, then connectors will be allowed to generate more than the maximum number of tasks, and existing sets of tasks that exceed the tasks.max property will be allowed to run. This property is deprecated and will be removed in an upcoming major release.
Type: boolean Default: true Valid Values: Importance: low key.converter
Converter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the keys in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro.
Type: class Default: null Valid Values: A concrete subclass of org.apache.kafka.connect.storage.Converter, A class with a public, no-argument constructor Importance: low value.converter
Converter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the values in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro.
Type: class Default: null Valid Values: A concrete subclass of org.apache.kafka.connect.storage.Converter, A class with a public, no-argument constructor Importance: low header.converter
HeaderConverter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the header values in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro. By default, the SimpleHeaderConverter is used to serialize header values to strings and deserialize them by inferring the schemas.
Type: class Default: null Valid Values: A concrete subclass of org.apache.kafka.connect.storage.HeaderConverter, A class with a public, no-argument constructor Importance: low config.action.reload
The action that Connect should take on the connector when changes in external configuration providers result in a change in the connector's configuration properties. A value of 'none' indicates that Connect will do nothing. A value of 'restart' indicates that Connect should restart/reload the connector with the updated configuration properties.The restart may actually be scheduled in the future if the external configuration provider indicates that a configuration value will expire in the future.
Type: string Default: restart Valid Values: [none, restart] Importance: low transforms
Aliases for the transformations to be applied to records.
Type: list Default: "" Valid Values: non-null string, unique transformation aliases Importance: low predicates
Aliases for the predicates used by transformations.
Type: list Default: "" Valid Values: non-null string, unique predicate aliases Importance: low errors.retry.timeout
The maximum duration in milliseconds that a failed operation will be reattempted. The default is 0, which means no retries will be attempted. Use -1 for infinite retries.
Type: long Default: 0 Valid Values: Importance: medium errors.retry.delay.max.ms
The maximum duration in milliseconds between consecutive retry attempts. Jitter will be added to the delay once this limit is reached to prevent thundering herd issues.
Type: long Default: 60000 (1 minute) Valid Values: Importance: medium errors.tolerance
Behavior for tolerating errors during connector operation. 'none' is the default value and signals that any error will result in an immediate connector task failure; 'all' changes the behavior to skip over problematic records.
Type: string Default: none Valid Values: [none, all] Importance: medium errors.log.enable
If true, write each error and the details of the failed operation and problematic record to the Connect application log. This is 'false' by default, so that only errors that are not tolerated are reported.
Type: boolean Default: false Valid Values: Importance: medium errors.log.include.messages
Whether to include in the log the Connect record that resulted in a failure. For sink records, the topic, partition, offset, and timestamp will be logged. For source records, the key and value (and their schemas), all headers, and the timestamp, Kafka topic, Kafka partition, source partition, and source offset will be logged. This is 'false' by default, which will prevent record keys, values, and headers from being written to log files.
Type: boolean Default: false Valid Values: Importance: medium errors.deadletterqueue.topic.name
The name of the topic to be used as the dead letter queue (DLQ) for messages that result in an error when processed by this sink connector, or its transformations or converters. The topic name is blank by default, which means that no messages are to be recorded in the DLQ.
Type: string Default: "" Valid Values: Importance: medium errors.deadletterqueue.topic.replication.factor
Replication factor used to create the dead letter queue topic when it doesn't already exist.
Type: short Default: 3 Valid Values: Importance: medium errors.deadletterqueue.context.headers.enable
If true, add headers containing error context to the messages written to the dead letter queue. To avoid clashing with headers from the original record, all error context header keys, all error context header keys will start with
__connect.errors.Type: boolean Default: false Valid Values: Importance: medium
Kafka Streams Configs
Below is the configuration of the Kafka Streams client library.
application.id
An identifier for the stream processing application. Must be unique within the Kafka cluster. It is used as 1) the default client-id prefix, 2) the group-id for membership management, 3) the changelog topic prefix.
Type: string Default: Valid Values: Importance: high bootstrap.servers
A list of host/port pairs used to establish the initial connection to the Kafka cluster. Clients use this list to bootstrap and discover the full set of Kafka brokers. While the order of servers in the list does not matter, we recommend including more than one server to ensure resilience if any servers are down. This list does not need to contain the entire set of brokers, as Kafka clients automatically manage and update connections to the cluster efficiently. This list must be in the form
host1:port1,host2:port2,....Type: list Default: Valid Values: Importance: high num.standby.replicas
The number of standby replicas for each task.
Type: int Default: 0 Valid Values: Importance: high state.dir
Directory location for state store. This path must be unique for each streams instance sharing the same underlying filesystem. Note that if not configured, then the default location will be different in each environment as it is computed using System.getProperty("java.io.tmpdir")
Type: string Default: ${java.io.tmpdir} Valid Values: Importance: high acceptable.recovery.lag
The maximum acceptable lag (number of offsets to catch up) for a client to be considered caught-up enough to receive an active task assignment. Upon assignment, it will still restore the rest of the changelog before processing. To avoid a pause in processing during rebalances, this config should correspond to a recovery time of well under a minute for a given workload. Must be at least 0.
Type: long Default: 10000 Valid Values: [0,...] Importance: medium cache.max.bytes.buffering
Maximum number of memory bytes to be used for buffering across all threads
Type: long Default: 10485760 Valid Values: [0,...] Importance: medium client.id
An ID prefix string used for the client IDs of internal (main, restore, and global) consumers , producers, and admin clients with pattern
<client.id>-[Global]StreamThread[-<threadSequenceNumber>]-<consumer|producer|restore-consumer|global-consumer>.Type: string Default: <application.id>-<random-UUID>Valid Values: Importance: medium default.deserialization.exception.handler
Exception handling class that implements the
org.apache.kafka.streams.errors.DeserializationExceptionHandlerinterface.Type: class Default: org.apache.kafka.streams.errors.LogAndFailExceptionHandler Valid Values: Importance: medium default.key.serde
Default serializer / deserializer class for key that implements the
org.apache.kafka.common.serialization.Serdeinterface.Type: class Default: null Valid Values: Importance: medium default.list.key.serde.inner
Default inner class of list serde for key that implements the
org.apache.kafka.common.serialization.Serdeinterface. This configuration will be read if and only ifdefault.key.serdeconfiguration is set toorg.apache.kafka.common.serialization.Serdes.ListSerdeType: class Default: null Valid Values: Importance: medium default.list.key.serde.type
Default class for key that implements the
java.util.Listinterface. This configuration will be read if and only ifdefault.key.serdeconfiguration is set toorg.apache.kafka.common.serialization.Serdes.ListSerdeNote when list serde class is used, one needs to set the inner serde class that implements theorg.apache.kafka.common.serialization.Serdeinterface via 'default.list.key.serde.inner'Type: class Default: null Valid Values: Importance: medium default.list.value.serde.inner
Default inner class of list serde for value that implements the
org.apache.kafka.common.serialization.Serdeinterface. This configuration will be read if and only ifdefault.value.serdeconfiguration is set toorg.apache.kafka.common.serialization.Serdes.ListSerdeType: class Default: null Valid Values: Importance: medium default.list.value.serde.type
Default class for value that implements the
java.util.Listinterface. This configuration will be read if and only ifdefault.value.serdeconfiguration is set toorg.apache.kafka.common.serialization.Serdes.ListSerdeNote when list serde class is used, one needs to set the inner serde class that implements theorg.apache.kafka.common.serialization.Serdeinterface via 'default.list.value.serde.inner'Type: class Default: null Valid Values: Importance: medium default.production.exception.handler
Exception handling class that implements the
org.apache.kafka.streams.errors.ProductionExceptionHandlerinterface.Type: class Default: org.apache.kafka.streams.errors.DefaultProductionExceptionHandler Valid Values: Importance: medium default.timestamp.extractor
Default timestamp extractor class that implements the
org.apache.kafka.streams.processor.TimestampExtractorinterface.Type: class Default: org.apache.kafka.streams.processor.FailOnInvalidTimestamp Valid Values: Importance: medium default.value.serde
Default serializer / deserializer class for value that implements the
org.apache.kafka.common.serialization.Serdeinterface.Type: class Default: null Valid Values: Importance: medium deserialization.exception.handler
Exception handling class that implements the
org.apache.kafka.streams.errors.DeserializationExceptionHandlerinterface.Type: class Default: org.apache.kafka.streams.errors.LogAndFailExceptionHandler Valid Values: Importance: medium max.task.idle.ms
This config controls whether joins and merges may produce out-of-order results. The config value is the maximum amount of time in milliseconds a stream task will stay idle when it is fully caught up on some (but not all) input partitions to wait for producers to send additional records and avoid potential out-of-order record processing across multiple input streams. The default (zero) does not wait for producers to send more records, but it does wait to fetch data that is already present on the brokers. This default means that for records that are already present on the brokers, Streams will process them in timestamp order. Set to -1 to disable idling entirely and process any locally available data, even though doing so may produce out-of-order processing.
Type: long Default: 0 Valid Values: Importance: medium max.warmup.replicas
The maximum number of warmup replicas (extra standbys beyond the configured num.standbys) that can be assigned at once for the purpose of keeping the task available on one instance while it is warming up on another instance it has been reassigned to. Used to throttle how much extra broker traffic and cluster state can be used for high availability. Must be at least 1.Note that one warmup replica corresponds to one Stream Task. Furthermore, note that each warmup replica can only be promoted to an active task during a rebalance (normally during a so-called probing rebalance, which occur at a frequency specified by the `probing.rebalance.interval.ms` config). This means that the maximum rate at which active tasks can be migrated from one Kafka Streams Instance to another instance can be determined by (`max.warmup.replicas` / `probing.rebalance.interval.ms`).
Type: int Default: 2 Valid Values: [1,...] Importance: medium num.stream.threads
The number of threads to execute stream processing.
Type: int Default: 1 Valid Values: Importance: medium processing.exception.handler
Exception handling class that implements the
org.apache.kafka.streams.errors.ProcessingExceptionHandlerinterface.Type: class Default: org.apache.kafka.streams.errors.LogAndFailProcessingExceptionHandler Valid Values: Importance: medium processing.guarantee
The processing guarantee that should be used. Possible values are
at_least_once(default) andexactly_once_v2(requires brokers version 2.5 or higher). Note that exactly-once processing requires a cluster of at least three brokers by default what is the recommended setting for production; for development you can change this, by adjusting broker settingtransaction.state.log.replication.factorandtransaction.state.log.min.isr.Type: string Default: at_least_once Valid Values: [at_least_once, exactly_once_v2] Importance: medium production.exception.handler
Exception handling class that implements the
org.apache.kafka.streams.errors.ProductionExceptionHandlerinterface.Type: class Default: org.apache.kafka.streams.errors.DefaultProductionExceptionHandler Valid Values: Importance: medium replication.factor
The replication factor for change log topics and repartition topics created by the stream processing application. The default of
-1(meaning: use broker default replication factor) requires broker version 2.4 or newerType: int Default: -1 Valid Values: Importance: medium security.protocol
Protocol used to communicate with brokers.
Type: string Default: PLAINTEXT Valid Values: (case insensitive) [SASL_SSL, PLAINTEXT, SSL, SASL_PLAINTEXT] Importance: medium statestore.cache.max.bytes
Maximum number of memory bytes to be used for statestore cache across all threads
Type: long Default: 10485760 (10 mebibytes) Valid Values: [0,...] Importance: medium task.assignor.class
A task assignor class or class name implementing the
org.apache.kafka.streams.processor.assignment.TaskAssignorinterface. Defaults to theHighAvailabilityTaskAssignorclass.Type: string Default: null Valid Values: Importance: medium task.timeout.ms
The maximum amount of time in milliseconds a task might stall due to internal errors and retries until an error is raised. For a timeout of 0ms, a task would raise an error for the first internal error. For any timeout larger than 0ms, a task will retry at least once before an error is raised.
Type: long Default: 300000 (5 minutes) Valid Values: [0,...] Importance: medium topology.optimization
A configuration telling Kafka Streams if it should optimize the topology and what optimizations to apply. Acceptable values are: "+NO_OPTIMIZATION+", "+OPTIMIZE+", or a comma separated list of specific optimizations: ("+REUSE_KTABLE_SOURCE_TOPICS+", "+MERGE_REPARTITION_TOPICS+" + "SINGLE_STORE_SELF_JOIN+")."NO_OPTIMIZATION" by default.
Type: string Default: none Valid Values: [all, none, reuse.ktable.source.topics, merge.repartition.topics, single.store.self.join] Importance: medium application.server
A host:port pair pointing to a user-defined endpoint that can be used for state store discovery and interactive queries on this KafkaStreams instance.
Type: string Default: "" Valid Values: Importance: low buffered.records.per.partition
Maximum number of records to buffer per partition.
Type: int Default: 1000 Valid Values: Importance: low built.in.metrics.version
Version of the built-in metrics to use.
Type: string Default: latest Valid Values: [latest] Importance: low commit.interval.ms
The frequency in milliseconds with which to commit processing progress. For at-least-once processing, committing means to save the position (ie, offsets) of the processor. For exactly-once processing, it means to commit the transaction which includes to save the position and to make the committed data in the output topic visible to consumers with isolation level read_committed. (Note, if
processing.guaranteeis set toexactly_once_v2, the default value is100, otherwise the default value is30000.Type: long Default: 30000 (30 seconds) Valid Values: [0,...] Importance: low connections.max.idle.ms
Close idle connections after the number of milliseconds specified by this config.
Type: long Default: 540000 (9 minutes) Valid Values: Importance: low default.client.supplier
Client supplier class that implements the
org.apache.kafka.streams.KafkaClientSupplierinterface.Type: class Default: org.apache.kafka.streams.processor.internals.DefaultKafkaClientSupplier Valid Values: Importance: low default.dsl.store
The default state store type used by DSL operators.
Type: string Default: rocksDB Valid Values: [rocksDB, in_memory] Importance: low dsl.store.suppliers.class
Defines which store implementations to plug in to DSL operators. Must implement the
org.apache.kafka.streams.state.DslStoreSuppliersinterface.Type: class Default: org.apache.kafka.streams.state.BuiltInDslStoreSuppliers$RocksDBDslStoreSuppliers Valid Values: Importance: low enable.metrics.push
Whether to enable pushing of internal client metrics for (main, restore, and global) consumers, producers, and admin clients. The cluster must have a client metrics subscription which corresponds to a client.
Type: boolean Default: true Valid Values: Importance: low log.summary.interval.ms
The output interval in milliseconds for logging summary information.
If greater or equal to 0, the summary log will be output according to the set time interval;
If less than 0, summary output is disabled.Type: long Default: 120000 (2 minutes) Valid Values: Importance: low metadata.max.age.ms
The period of time in milliseconds after which we force a refresh of metadata even if we haven't seen any partition leadership changes to proactively discover any new brokers or partitions.
Type: long Default: 300000 (5 minutes) Valid Values: [0,...] Importance: low metadata.recovery.rebootstrap.trigger.ms
If a client configured to rebootstrap using
metadata.recovery.strategy=rebootstrapis unable to obtain metadata from any of the brokers in the last known metadata for this interval, client repeats the bootstrap process usingbootstrap.serversconfiguration.Type: long Default: 300000 (5 minutes) Valid Values: [0,...] Importance: low metadata.recovery.strategy
Controls how the client recovers when none of the brokers known to it is available. If set to
none, the client fails. If set torebootstrap, the client repeats the bootstrap process usingbootstrap.servers. Rebootstrapping is useful when a client communicates with brokers so infrequently that the set of brokers may change entirely before the client refreshes metadata. Metadata recovery is triggered when all last-known brokers appear unavailable simultaneously. Brokers appear unavailable when disconnected and no current retry attempt is in-progress. Consider increasingreconnect.backoff.msandreconnect.backoff.max.msand decreasingsocket.connection.setup.timeout.msandsocket.connection.setup.timeout.max.msfor the client. Rebootstrap is also triggered if connection cannot be established to any of the brokers formetadata.recovery.rebootstrap.trigger.msmilliseconds or if server requests rebootstrap.Type: string Default: rebootstrap Valid Values: (case insensitive) [REBOOTSTRAP, NONE] Importance: low metric.reporters
A list of classes to use as metrics reporters. Implementing the
org.apache.kafka.common.metrics.MetricsReporterinterface allows plugging in classes that will be notified of new metric creation.Type: list Default: org.apache.kafka.common.metrics.JmxReporter Valid Values: Importance: low metrics.num.samples
The number of samples maintained to compute metrics.
Type: int Default: 2 Valid Values: [1,...] Importance: low metrics.recording.level
The highest recording level for metrics. It has three levels for recording metrics - info, debug, and trace.
INFO level records only essential metrics necessary for monitoring system performance and health. It collects vital data without gathering too much detail, making it suitable for production environments where minimal overhead is desired.
DEBUG level records most metrics, providing more detailed information about the system's operation. It's useful for development and testing environments where you need deeper insights to debug and fine-tune the application.
TRACE level records all possible metrics, capturing every detail about the system's performance and operation. It's best for controlled environments where in-depth analysis is required, though it can introduce significant overhead.Type: string Default: INFO Valid Values: [INFO, DEBUG, TRACE] Importance: low metrics.sample.window.ms
The window of time a metrics sample is computed over.
Type: long Default: 30000 (30 seconds) Valid Values: [0,...] Importance: low poll.ms
The amount of time in milliseconds to block waiting for input.
Type: long Default: 100 Valid Values: Importance: low probing.rebalance.interval.ms
The maximum time in milliseconds to wait before triggering a rebalance to probe for warmup replicas that have finished warming up and are ready to become active. Probing rebalances will continue to be triggered until the assignment is balanced. Must be at least 1 minute.
Type: long Default: 600000 (10 minutes) Valid Values: [60000,...] Importance: low processor.wrapper.class
A processor wrapper class or class name that implements the
org.apache.kafka.streams.state.ProcessorWrapperinterface. Must be passed in to the StreamsBuilder or Topology constructor in order to take effectType: class Default: org.apache.kafka.streams.processor.internals.NoOpProcessorWrapper Valid Values: Importance: low rack.aware.assignment.non_overlap_cost
Cost associated with moving tasks from existing assignment. This config and
rack.aware.assignment.traffic_costcontrols whether the optimization algorithm favors minimizing cross rack traffic or minimize the movement of tasks in existing assignment. If set a larger valueorg.apache.kafka.streams.processor.internals.assignment.RackAwareTaskAssignorwill optimize to maintain the existing assignment. The default value is null which means it will use default non_overlap cost values in different assignors.Type: int Default: null Valid Values: Importance: low rack.aware.assignment.strategy
The strategy we use for rack aware assignment. Rack aware assignment will take
client.rackandracksofTopicPartitioninto account when assigning tasks to minimize cross rack traffic. Valid settings are :none(default), which will disable rack aware assignment;min_traffic, which will compute minimum cross rack traffic assignment;balance_subtopology, which will compute minimum cross rack traffic and try to balance the tasks of same subtopologies across different clientsType: string Default: none Valid Values: [none, min_traffic, balance_subtopology] Importance: low rack.aware.assignment.tags
List of client tag keys used to distribute standby replicas across Kafka Streams instances. When configured, Kafka Streams will make a best-effort to distribute the standby tasks over each client tag dimension.
Type: list Default: "" Valid Values: List containing maximum of 5 elements Importance: low rack.aware.assignment.traffic_cost
Cost associated with cross rack traffic. This config and
rack.aware.assignment.non_overlap_costcontrols whether the optimization algorithm favors minimizing cross rack traffic or minimize the movement of tasks in existing assignment. If set a larger valueorg.apache.kafka.streams.processor.internals.assignment.RackAwareTaskAssignorwill optimize for minimizing cross rack traffic. The default value is null which means it will use default traffic cost values in different assignors.Type: int Default: null Valid Values: Importance: low receive.buffer.bytes
The size of the TCP receive buffer (SO_RCVBUF) to use when reading data. If the value is -1, the OS default will be used.
Type: int Default: 32768 (32 kibibytes) Valid Values: [-1,...] Importance: low reconnect.backoff.max.ms
The maximum amount of time in milliseconds to wait when reconnecting to a broker that has repeatedly failed to connect. If provided, the backoff per host will increase exponentially for each consecutive connection failure, up to this maximum. After calculating the backoff increase, 20% random jitter is added to avoid connection storms.
Type: long Default: 1000 (1 second) Valid Values: [0,...] Importance: low reconnect.backoff.ms
The base amount of time to wait before attempting to reconnect to a given host. This avoids repeatedly connecting to a host in a tight loop. This backoff applies to all connection attempts by the client to a broker. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the
reconnect.backoff.max.msvalue.Type: long Default: 50 Valid Values: [0,...] Importance: low repartition.purge.interval.ms
The frequency in milliseconds with which to delete fully consumed records from repartition topics. Purging will occur after at least this value since the last purge, but may be delayed until later. (Note, unlike
commit.interval.ms, the default for this value remains unchanged whenprocessing.guaranteeis set toexactly_once_v2).Type: long Default: 30000 (30 seconds) Valid Values: [0,...] Importance: low request.timeout.ms
The configuration controls the maximum amount of time the client will wait for the response of a request. If the response is not received before the timeout elapses the client will resend the request if necessary or fail the request if retries are exhausted.
Type: int Default: 40000 (40 seconds) Valid Values: [0,...] Importance: low retry.backoff.ms
The amount of time to wait before attempting to retry a failed request to a given topic partition. This avoids repeatedly sending requests in a tight loop under some failure scenarios. This value is the initial backoff value and will increase exponentially for each failed request, up to the
retry.backoff.max.msvalue.Type: long Default: 100 Valid Values: [0,...] Importance: low rocksdb.config.setter
A Rocks DB config setter class or class name that implements the
org.apache.kafka.streams.state.RocksDBConfigSetterinterfaceType: class Default: null Valid Values: Importance: low send.buffer.bytes
The size of the TCP send buffer (SO_SNDBUF) to use when sending data. If the value is -1, the OS default will be used.
Type: int Default: 131072 (128 kibibytes) Valid Values: [-1,...] Importance: low state.cleanup.delay.ms
The amount of time in milliseconds to wait before deleting state when a partition has migrated. Only state directories that have not been modified for at least
state.cleanup.delay.mswill be removedType: long Default: 600000 (10 minutes) Valid Values: Importance: low upgrade.from
Allows live upgrading (and downgrading in some cases -- see upgrade guide) in a backward compatible way. Default is `null`. Please refer to the Kafka Streams upgrade guide for instructions on how and when to use this config. Note that when upgrading from 3.5 to a newer version it is never required to specify this config, while upgrading live directly to 4.0+ from 2.3 or below is no longer supported even with this config. Accepted values are "2.4", "2.5", "2.6", "2.7", "2.8", "3.0", "3.1", "3.2", "3.3", "3.4", "3.5", "3.6", "3.7", "3.8", "3.9", "(for upgrading from the corresponding old version).
Type: string Default: null Valid Values: [null, 0.10.0, 0.10.1, 0.10.2, 0.11.0, 1.0, 1.1, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9] Importance: low window.size.ms
Sets window size for the deserializer in order to calculate window end times.
Type: long Default: null Valid Values: Importance: low windowed.inner.class.serde
Default serializer / deserializer for the inner class of a windowed record. Must implement the
org.apache.kafka.common.serialization.Serdeinterface. Note that setting this config in KafkaStreams application would result in an error as it is meant to be used only from Plain consumer client.Type: string Default: null Valid Values: Importance: low windowstore.changelog.additional.retention.ms
Added to a windows maintainMs to ensure data is not deleted from the log prematurely. Allows for clock drift. Default is 1 day
Type: long Default: 86400000 (1 day) Valid Values: Importance: low
Admin Configs
Below is the configuration of the Kafka Admin client library.
bootstrap.controllers
A list of host/port pairs to use for establishing the initial connection to the KRaft controller quorum. This list should be in the form
host1:port1,host2:port2,....Type: list Default: "" Valid Values: Importance: high bootstrap.servers
A list of host/port pairs used to establish the initial connection to the Kafka cluster. Clients use this list to bootstrap and discover the full set of Kafka brokers. While the order of servers in the list does not matter, we recommend including more than one server to ensure resilience if any servers are down. This list does not need to contain the entire set of brokers, as Kafka clients automatically manage and update connections to the cluster efficiently. This list must be in the form
host1:port1,host2:port2,....Type: list Default: "" Valid Values: Importance: high ssl.key.password
The password of the private key in the key store file or the PEM key specified in 'ssl.keystore.key'.
Type: password Default: null Valid Values: Importance: high ssl.keystore.certificate.chain
Certificate chain in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with a list of X.509 certificates
Type: password Default: null Valid Values: Importance: high ssl.keystore.key
Private key in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with PKCS#8 keys. If the key is encrypted, key password must be specified using 'ssl.key.password'
Type: password Default: null Valid Values: Importance: high ssl.keystore.location
The location of the key store file. This is optional for client and can be used for two-way authentication for client.
Type: string Default: null Valid Values: Importance: high ssl.keystore.password
The store password for the key store file. This is optional for client and only needed if 'ssl.keystore.location' is configured. Key store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: high ssl.truststore.certificates
Trusted certificates in the format specified by 'ssl.truststore.type'. Default SSL engine factory supports only PEM format with X.509 certificates.
Type: password Default: null Valid Values: Importance: high ssl.truststore.location
The location of the trust store file.
Type: string Default: null Valid Values: Importance: high ssl.truststore.password
The password for the trust store file. If a password is not set, trust store file configured will still be used, but integrity checking is disabled. Trust store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: high client.dns.lookup
Controls how the client uses DNS lookups. If set to
use_all_dns_ips, connect to each returned IP address in sequence until a successful connection is established. After a disconnection, the next IP is used. Once all IPs have been used once, the client resolves the IP(s) from the hostname again (both the JVM and the OS cache DNS name lookups, however). If set toresolve_canonical_bootstrap_servers_only, resolve each bootstrap address into a list of canonical names. After the bootstrap phase, this behaves the same asuse_all_dns_ips.Type: string Default: use_all_dns_ips Valid Values: [use_all_dns_ips, resolve_canonical_bootstrap_servers_only] Importance: medium client.id
An id string to pass to the server when making requests. The purpose of this is to be able to track the source of requests beyond just ip/port by allowing a logical application name to be included in server-side request logging.
Type: string Default: "" Valid Values: Importance: medium connections.max.idle.ms
Close idle connections after the number of milliseconds specified by this config.
Type: long Default: 300000 (5 minutes) Valid Values: Importance: medium default.api.timeout.ms
Specifies the timeout (in milliseconds) for client APIs. This configuration is used as the default timeout for all client operations that do not specify a
timeoutparameter.Type: int Default: 60000 (1 minute) Valid Values: [0,...] Importance: medium receive.buffer.bytes
The size of the TCP receive buffer (SO_RCVBUF) to use when reading data. If the value is -1, the OS default will be used.
Type: int Default: 65536 (64 kibibytes) Valid Values: [-1,...] Importance: medium request.timeout.ms
The configuration controls the maximum amount of time the client will wait for the response of a request. If the response is not received before the timeout elapses the client will resend the request if necessary or fail the request if retries are exhausted.
Type: int Default: 30000 (30 seconds) Valid Values: [0,...] Importance: medium sasl.client.callback.handler.class
The fully qualified name of a SASL client callback handler class that implements the AuthenticateCallbackHandler interface.
Type: class Default: null Valid Values: Importance: medium sasl.jaas.config
JAAS login context parameters for SASL connections in the format used by JAAS configuration files. JAAS configuration file format is described here. The format for the value is:
loginModuleClass controlFlag (optionName=optionValue)*;. For brokers, the config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.jaas.config=com.example.ScramLoginModule required;Type: password Default: null Valid Values: Importance: medium sasl.kerberos.service.name
The Kerberos principal name that Kafka runs as. This can be defined either in Kafka's JAAS config or in Kafka's config.
Type: string Default: null Valid Values: Importance: medium sasl.login.callback.handler.class
The fully qualified name of a SASL login callback handler class that implements the AuthenticateCallbackHandler interface. For brokers, login callback handler config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.callback.handler.class=com.example.CustomScramLoginCallbackHandler
Type: class Default: null Valid Values: Importance: medium sasl.login.class
The fully qualified name of a class that implements the Login interface. For brokers, login config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.class=com.example.CustomScramLogin
Type: class Default: null Valid Values: Importance: medium sasl.mechanism
SASL mechanism used for client connections. This may be any mechanism for which a security provider is available. GSSAPI is the default mechanism.
Type: string Default: GSSAPI Valid Values: Importance: medium sasl.oauthbearer.jwks.endpoint.url
The OAuth/OIDC provider URL from which the provider's JWKS (JSON Web Key Set) can be retrieved. The URL can be HTTP(S)-based or file-based. If the URL is HTTP(S)-based, the JWKS data will be retrieved from the OAuth/OIDC provider via the configured URL on broker startup. All then-current keys will be cached on the broker for incoming requests. If an authentication request is received for a JWT that includes a "kid" header claim value that isn't yet in the cache, the JWKS endpoint will be queried again on demand. However, the broker polls the URL every sasl.oauthbearer.jwks.endpoint.refresh.ms milliseconds to refresh the cache with any forthcoming keys before any JWT requests that include them are received. If the URL is file-based, the broker will load the JWKS file from a configured location on startup. In the event that the JWT includes a "kid" header value that isn't in the JWKS file, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: medium sasl.oauthbearer.token.endpoint.url
The URL for the OAuth/OIDC identity provider. If the URL is HTTP(S)-based, it is the issuer's token endpoint URL to which requests will be made to login based on the configuration in sasl.jaas.config. If the URL is file-based, it specifies a file containing an access token (in JWT serialized form) issued by the OAuth/OIDC identity provider to use for authorization.
Type: string Default: null Valid Values: Importance: medium security.protocol
Protocol used to communicate with brokers.
Type: string Default: PLAINTEXT Valid Values: (case insensitive) [SASL_SSL, PLAINTEXT, SSL, SASL_PLAINTEXT] Importance: medium send.buffer.bytes
The size of the TCP send buffer (SO_SNDBUF) to use when sending data. If the value is -1, the OS default will be used.
Type: int Default: 131072 (128 kibibytes) Valid Values: [-1,...] Importance: medium socket.connection.setup.timeout.max.ms
The maximum amount of time the client will wait for the socket connection to be established. The connection setup timeout will increase exponentially for each consecutive connection failure up to this maximum. To avoid connection storms, a randomization factor of 0.2 will be applied to the timeout resulting in a random range between 20% below and 20% above the computed value.
Type: long Default: 30000 (30 seconds) Valid Values: Importance: medium socket.connection.setup.timeout.ms
The amount of time the client will wait for the socket connection to be established. If the connection is not built before the timeout elapses, clients will close the socket channel. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the
socket.connection.setup.timeout.max.msvalue.Type: long Default: 10000 (10 seconds) Valid Values: Importance: medium ssl.enabled.protocols
The list of protocols enabled for SSL connections. The default is 'TLSv1.2,TLSv1.3'. This means that clients and servers will prefer TLSv1.3 if both support it and fallback to TLSv1.2 otherwise (assuming both support at least TLSv1.2). This default should be fine for most use cases. Also see the config documentation for `ssl.protocol` to understand how it can impact the TLS version negotiation behavior.
Type: list Default: TLSv1.2,TLSv1.3 Valid Values: Importance: medium ssl.keystore.type
The file format of the key store file. This is optional for client. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium ssl.protocol
The SSL protocol used to generate the SSLContext. The default is 'TLSv1.3', which should be fine for most use cases. A typical alternative to the default is 'TLSv1.2'. Allowed values for this config are dependent on the JVM. Clients using the defaults for this config and 'ssl.enabled.protocols' will downgrade to 'TLSv1.2' if the server does not support 'TLSv1.3'. If this config is set to 'TLSv1.2', however, clients will not use 'TLSv1.3' even if it is one of the values in `ssl.enabled.protocols` and the server only supports 'TLSv1.3'.
Type: string Default: TLSv1.3 Valid Values: Importance: medium ssl.provider
The name of the security provider used for SSL connections. Default value is the default security provider of the JVM.
Type: string Default: null Valid Values: Importance: medium ssl.truststore.type
The file format of the trust store file. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium enable.metrics.push
Whether to enable pushing of client metrics to the cluster, if the cluster has a client metrics subscription which matches this client.
Type: boolean Default: false Valid Values: Importance: low metadata.max.age.ms
The period of time in milliseconds after which we force a refresh of metadata even if we haven't seen any partition leadership changes to proactively discover any new brokers or partitions.
Type: long Default: 300000 (5 minutes) Valid Values: [0,...] Importance: low metadata.recovery.rebootstrap.trigger.ms
If a client configured to rebootstrap using
metadata.recovery.strategy=rebootstrapis unable to obtain metadata from any of the brokers in the last known metadata for this interval, client repeats the bootstrap process usingbootstrap.serversconfiguration.Type: long Default: 300000 (5 minutes) Valid Values: [0,...] Importance: low metadata.recovery.strategy
Controls how the client recovers when none of the brokers known to it is available. If set to
none, the client fails. If set torebootstrap, the client repeats the bootstrap process usingbootstrap.servers. Rebootstrapping is useful when a client communicates with brokers so infrequently that the set of brokers may change entirely before the client refreshes metadata. Metadata recovery is triggered when all last-known brokers appear unavailable simultaneously. Brokers appear unavailable when disconnected and no current retry attempt is in-progress. Consider increasingreconnect.backoff.msandreconnect.backoff.max.msand decreasingsocket.connection.setup.timeout.msandsocket.connection.setup.timeout.max.msfor the client. Rebootstrap is also triggered if connection cannot be established to any of the brokers formetadata.recovery.rebootstrap.trigger.msmilliseconds or if server requests rebootstrap.Type: string Default: rebootstrap Valid Values: (case insensitive) [REBOOTSTRAP, NONE] Importance: low metric.reporters
A list of classes to use as metrics reporters. Implementing the
org.apache.kafka.common.metrics.MetricsReporterinterface allows plugging in classes that will be notified of new metric creation.Type: list Default: org.apache.kafka.common.metrics.JmxReporter Valid Values: Importance: low metrics.num.samples
The number of samples maintained to compute metrics.
Type: int Default: 2 Valid Values: [1,...] Importance: low metrics.recording.level
The highest recording level for metrics. It has three levels for recording metrics - info, debug, and trace.
INFO level records only essential metrics necessary for monitoring system performance and health. It collects vital data without gathering too much detail, making it suitable for production environments where minimal overhead is desired.
DEBUG level records most metrics, providing more detailed information about the system's operation. It's useful for development and testing environments where you need deeper insights to debug and fine-tune the application.
TRACE level records all possible metrics, capturing every detail about the system's performance and operation. It's best for controlled environments where in-depth analysis is required, though it can introduce significant overhead.Type: string Default: INFO Valid Values: [INFO, DEBUG, TRACE] Importance: low metrics.sample.window.ms
The window of time a metrics sample is computed over.
Type: long Default: 30000 (30 seconds) Valid Values: [0,...] Importance: low reconnect.backoff.max.ms
The maximum amount of time in milliseconds to wait when reconnecting to a broker that has repeatedly failed to connect. If provided, the backoff per host will increase exponentially for each consecutive connection failure, up to this maximum. After calculating the backoff increase, 20% random jitter is added to avoid connection storms.
Type: long Default: 1000 (1 second) Valid Values: [0,...] Importance: low reconnect.backoff.ms
The base amount of time to wait before attempting to reconnect to a given host. This avoids repeatedly connecting to a host in a tight loop. This backoff applies to all connection attempts by the client to a broker. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the
reconnect.backoff.max.msvalue.Type: long Default: 50 Valid Values: [0,...] Importance: low retries
Setting a value greater than zero will cause the client to resend any request that fails with a potentially transient error. It is recommended to set the value to either zero or `MAX_VALUE` and use corresponding timeout parameters to control how long a client should retry a request.
Type: int Default: 2147483647 Valid Values: [0,...,2147483647] Importance: low retry.backoff.max.ms
The maximum amount of time in milliseconds to wait when retrying a request to the broker that has repeatedly failed. If provided, the backoff per client will increase exponentially for each failed request, up to this maximum. To prevent all clients from being synchronized upon retry, a randomized jitter with a factor of 0.2 will be applied to the backoff, resulting in the backoff falling within a range between 20% below and 20% above the computed value. If
retry.backoff.msis set to be higher thanretry.backoff.max.ms, thenretry.backoff.max.mswill be used as a constant backoff from the beginning without any exponential increaseType: long Default: 1000 (1 second) Valid Values: [0,...] Importance: low retry.backoff.ms
The amount of time to wait before attempting to retry a failed request to a given topic partition. This avoids repeatedly sending requests in a tight loop under some failure scenarios. This value is the initial backoff value and will increase exponentially for each failed request, up to the
retry.backoff.max.msvalue.Type: long Default: 100 Valid Values: [0,...] Importance: low sasl.kerberos.kinit.cmd
Kerberos kinit command path.
Type: string Default: /usr/bin/kinit Valid Values: Importance: low sasl.kerberos.min.time.before.relogin
Login thread sleep time between refresh attempts.
Type: long Default: 60000 Valid Values: Importance: low sasl.kerberos.ticket.renew.jitter
Percentage of random jitter added to the renewal time.
Type: double Default: 0.05 Valid Values: Importance: low sasl.kerberos.ticket.renew.window.factor
Login thread will sleep until the specified window factor of time from last refresh to ticket's expiry has been reached, at which time it will try to renew the ticket.
Type: double Default: 0.8 Valid Values: Importance: low sasl.login.connect.timeout.ms
The (optional) value in milliseconds for the external authentication provider connection timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low sasl.login.read.timeout.ms
The (optional) value in milliseconds for the external authentication provider read timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low sasl.login.refresh.buffer.seconds
The amount of buffer time before credential expiration to maintain when refreshing a credential, in seconds. If a refresh would otherwise occur closer to expiration than the number of buffer seconds then the refresh will be moved up to maintain as much of the buffer time as possible. Legal values are between 0 and 3600 (1 hour); a default value of 300 (5 minutes) is used if no value is specified. This value and sasl.login.refresh.min.period.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 300 Valid Values: [0,...,3600] Importance: low sasl.login.refresh.min.period.seconds
The desired minimum time for the login refresh thread to wait before refreshing a credential, in seconds. Legal values are between 0 and 900 (15 minutes); a default value of 60 (1 minute) is used if no value is specified. This value and sasl.login.refresh.buffer.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 60 Valid Values: [0,...,900] Importance: low sasl.login.refresh.window.factor
Login refresh thread will sleep until the specified window factor relative to the credential's lifetime has been reached, at which time it will try to refresh the credential. Legal values are between 0.5 (50%) and 1.0 (100%) inclusive; a default value of 0.8 (80%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.8 Valid Values: [0.5,...,1.0] Importance: low sasl.login.refresh.window.jitter
The maximum amount of random jitter relative to the credential's lifetime that is added to the login refresh thread's sleep time. Legal values are between 0 and 0.25 (25%) inclusive; a default value of 0.05 (5%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.05 Valid Values: [0.0,...,0.25] Importance: low sasl.login.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low sasl.login.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 100 Valid Values: Importance: low sasl.oauthbearer.clock.skew.seconds
The (optional) value in seconds to allow for differences between the time of the OAuth/OIDC identity provider and the broker.
Type: int Default: 30 Valid Values: Importance: low sasl.oauthbearer.expected.audience
The (optional) comma-delimited setting for the broker to use to verify that the JWT was issued for one of the expected audiences. The JWT will be inspected for the standard OAuth "aud" claim and if this value is set, the broker will match the value from JWT's "aud" claim to see if there is an exact match. If there is no match, the broker will reject the JWT and authentication will fail.
Type: list Default: null Valid Values: Importance: low sasl.oauthbearer.expected.issuer
The (optional) setting for the broker to use to verify that the JWT was created by the expected issuer. The JWT will be inspected for the standard OAuth "iss" claim and if this value is set, the broker will match it exactly against what is in the JWT's "iss" claim. If there is no match, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: low sasl.oauthbearer.header.urlencode
The (optional) setting to enable the OAuth client to URL-encode the client_id and client_secret in the authorization header in accordance with RFC6749, see here for more details. The default value is set to 'false' for backward compatibility
Type: boolean Default: false Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.refresh.ms
The (optional) value in milliseconds for the broker to wait between refreshing its JWKS (JSON Web Key Set) cache that contains the keys to verify the signature of the JWT.
Type: long Default: 3600000 (1 hour) Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between attempts to retrieve the JWKS (JSON Web Key Set) from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between JWKS (JSON Web Key Set) retrieval attempts from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 100 Valid Values: Importance: low sasl.oauthbearer.scope.claim.name
The OAuth claim for the scope is often named "scope", but this (optional) setting can provide a different name to use for the scope included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: scope Valid Values: Importance: low sasl.oauthbearer.sub.claim.name
The OAuth claim for the subject is often named "sub", but this (optional) setting can provide a different name to use for the subject included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: sub Valid Values: Importance: low security.providers
A list of configurable creator classes each returning a provider implementing security algorithms. These classes should implement the
org.apache.kafka.common.security.auth.SecurityProviderCreatorinterface.Type: string Default: null Valid Values: Importance: low ssl.cipher.suites
A list of cipher suites. This is a named combination of authentication, encryption, MAC and key exchange algorithm used to negotiate the security settings for a network connection using TLS or SSL network protocol. By default all the available cipher suites are supported.
Type: list Default: null Valid Values: Importance: low ssl.endpoint.identification.algorithm
The endpoint identification algorithm to validate server hostname using server certificate.
Type: string Default: https Valid Values: Importance: low ssl.engine.factory.class
The class of type org.apache.kafka.common.security.auth.SslEngineFactory to provide SSLEngine objects. Default value is org.apache.kafka.common.security.ssl.DefaultSslEngineFactory. Alternatively, setting this to org.apache.kafka.common.security.ssl.CommonNameLoggingSslEngineFactory will log the common name of expired SSL certificates used by clients to authenticate at any of the brokers with log level INFO. Note that this will cause a tiny delay during establishment of new connections from mTLS clients to brokers due to the extra code for examining the certificate chain provided by the client. Note further that the implementation uses a custom truststore based on the standard Java truststore and thus might be considered a security risk due to not being as mature as the standard one.
Type: class Default: null Valid Values: Importance: low ssl.keymanager.algorithm
The algorithm used by key manager factory for SSL connections. Default value is the key manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: SunX509 Valid Values: Importance: low ssl.secure.random.implementation
The SecureRandom PRNG implementation to use for SSL cryptography operations.
Type: string Default: null Valid Values: Importance: low ssl.trustmanager.algorithm
The algorithm used by trust manager factory for SSL connections. Default value is the trust manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: PKIX Valid Values: Importance: low
MirrorMaker Configs
Below is the configuration of the connectors that make up MirrorMaker 2.
MirrorMaker Common Configs
Below are the common configuration properties that apply to all three connectors.
source.cluster.alias
Alias of source cluster
Type: string Default: Valid Values: Importance: high ssl.key.password
The password of the private key in the key store file or the PEM key specified in 'ssl.keystore.key'.
Type: password Default: null Valid Values: Importance: high ssl.keystore.certificate.chain
Certificate chain in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with a list of X.509 certificates
Type: password Default: null Valid Values: Importance: high ssl.keystore.key
Private key in the format specified by 'ssl.keystore.type'. Default SSL engine factory supports only PEM format with PKCS#8 keys. If the key is encrypted, key password must be specified using 'ssl.key.password'
Type: password Default: null Valid Values: Importance: high ssl.keystore.location
The location of the key store file. This is optional for client and can be used for two-way authentication for client.
Type: string Default: null Valid Values: Importance: high ssl.keystore.password
The store password for the key store file. This is optional for client and only needed if 'ssl.keystore.location' is configured. Key store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: high ssl.truststore.certificates
Trusted certificates in the format specified by 'ssl.truststore.type'. Default SSL engine factory supports only PEM format with X.509 certificates.
Type: password Default: null Valid Values: Importance: high ssl.truststore.location
The location of the trust store file.
Type: string Default: null Valid Values: Importance: high ssl.truststore.password
The password for the trust store file. If a password is not set, trust store file configured will still be used, but integrity checking is disabled. Trust store password is not supported for PEM format.
Type: password Default: null Valid Values: Importance: high target.cluster.alias
Alias of target cluster. Used in metrics reporting.
Type: string Default: target Valid Values: Importance: high sasl.client.callback.handler.class
The fully qualified name of a SASL client callback handler class that implements the AuthenticateCallbackHandler interface.
Type: class Default: null Valid Values: Importance: medium sasl.jaas.config
JAAS login context parameters for SASL connections in the format used by JAAS configuration files. JAAS configuration file format is described here. The format for the value is:
loginModuleClass controlFlag (optionName=optionValue)*;. For brokers, the config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.jaas.config=com.example.ScramLoginModule required;Type: password Default: null Valid Values: Importance: medium sasl.kerberos.service.name
The Kerberos principal name that Kafka runs as. This can be defined either in Kafka's JAAS config or in Kafka's config.
Type: string Default: null Valid Values: Importance: medium sasl.login.callback.handler.class
The fully qualified name of a SASL login callback handler class that implements the AuthenticateCallbackHandler interface. For brokers, login callback handler config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.callback.handler.class=com.example.CustomScramLoginCallbackHandler
Type: class Default: null Valid Values: Importance: medium sasl.login.class
The fully qualified name of a class that implements the Login interface. For brokers, login config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.class=com.example.CustomScramLogin
Type: class Default: null Valid Values: Importance: medium sasl.mechanism
SASL mechanism used for client connections. This may be any mechanism for which a security provider is available. GSSAPI is the default mechanism.
Type: string Default: GSSAPI Valid Values: Importance: medium sasl.oauthbearer.jwks.endpoint.url
The OAuth/OIDC provider URL from which the provider's JWKS (JSON Web Key Set) can be retrieved. The URL can be HTTP(S)-based or file-based. If the URL is HTTP(S)-based, the JWKS data will be retrieved from the OAuth/OIDC provider via the configured URL on broker startup. All then-current keys will be cached on the broker for incoming requests. If an authentication request is received for a JWT that includes a "kid" header claim value that isn't yet in the cache, the JWKS endpoint will be queried again on demand. However, the broker polls the URL every sasl.oauthbearer.jwks.endpoint.refresh.ms milliseconds to refresh the cache with any forthcoming keys before any JWT requests that include them are received. If the URL is file-based, the broker will load the JWKS file from a configured location on startup. In the event that the JWT includes a "kid" header value that isn't in the JWKS file, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: medium sasl.oauthbearer.token.endpoint.url
The URL for the OAuth/OIDC identity provider. If the URL is HTTP(S)-based, it is the issuer's token endpoint URL to which requests will be made to login based on the configuration in sasl.jaas.config. If the URL is file-based, it specifies a file containing an access token (in JWT serialized form) issued by the OAuth/OIDC identity provider to use for authorization.
Type: string Default: null Valid Values: Importance: medium security.protocol
Protocol used to communicate with brokers.
Type: string Default: PLAINTEXT Valid Values: (case insensitive) [SASL_SSL, PLAINTEXT, SSL, SASL_PLAINTEXT] Importance: medium ssl.enabled.protocols
The list of protocols enabled for SSL connections. The default is 'TLSv1.2,TLSv1.3'. This means that clients and servers will prefer TLSv1.3 if both support it and fallback to TLSv1.2 otherwise (assuming both support at least TLSv1.2). This default should be fine for most use cases. Also see the config documentation for `ssl.protocol` to understand how it can impact the TLS version negotiation behavior.
Type: list Default: TLSv1.2,TLSv1.3 Valid Values: Importance: medium ssl.keystore.type
The file format of the key store file. This is optional for client. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium ssl.protocol
The SSL protocol used to generate the SSLContext. The default is 'TLSv1.3', which should be fine for most use cases. A typical alternative to the default is 'TLSv1.2'. Allowed values for this config are dependent on the JVM. Clients using the defaults for this config and 'ssl.enabled.protocols' will downgrade to 'TLSv1.2' if the server does not support 'TLSv1.3'. If this config is set to 'TLSv1.2', however, clients will not use 'TLSv1.3' even if it is one of the values in `ssl.enabled.protocols` and the server only supports 'TLSv1.3'.
Type: string Default: TLSv1.3 Valid Values: Importance: medium ssl.provider
The name of the security provider used for SSL connections. Default value is the default security provider of the JVM.
Type: string Default: null Valid Values: Importance: medium ssl.truststore.type
The file format of the trust store file. The values currently supported by the default `ssl.engine.factory.class` are [JKS, PKCS12, PEM].
Type: string Default: JKS Valid Values: Importance: medium admin.timeout.ms
Timeout for administrative tasks, e.g. detecting new topics.
Type: long Default: 60000 (1 minute) Valid Values: Importance: low enabled
Whether to replicate source->target.
Type: boolean Default: true Valid Values: Importance: low forwarding.admin.class
Class which extends ForwardingAdmin to define custom cluster resource management (topics, configs, etc). The class must have a constructor with signature
(Mapthat is used to configure a KafkaAdminClient and may also be used to configure clients for external systems if necessary.Type: class Default: org.apache.kafka.clients.admin.ForwardingAdmin Valid Values: Importance: low metric.reporters
A list of classes to use as metrics reporters. Implementing the
org.apache.kafka.common.metrics.MetricsReporterinterface allows plugging in classes that will be notified of new metric creation.Type: list Default: org.apache.kafka.common.metrics.JmxReporter Valid Values: Importance: low replication.policy.class
Class which defines the remote topic naming convention.
Type: class Default: org.apache.kafka.connect.mirror.DefaultReplicationPolicy Valid Values: Importance: low replication.policy.internal.topic.separator.enabled
Whether to use replication.policy.separator to control the names of topics used for checkpoints and offset syncs. By default, custom separators are used in these topic names; however, if upgrading MirrorMaker 2 from older versions that did not allow for these topic names to be customized, it may be necessary to set this property to 'false' in order to continue using the same names for those topics.
Type: boolean Default: true Valid Values: Importance: low replication.policy.separator
Separator used in remote topic naming convention.
Type: string Default: . Valid Values: Importance: low sasl.kerberos.kinit.cmd
Kerberos kinit command path.
Type: string Default: /usr/bin/kinit Valid Values: Importance: low sasl.kerberos.min.time.before.relogin
Login thread sleep time between refresh attempts.
Type: long Default: 60000 Valid Values: Importance: low sasl.kerberos.ticket.renew.jitter
Percentage of random jitter added to the renewal time.
Type: double Default: 0.05 Valid Values: Importance: low sasl.kerberos.ticket.renew.window.factor
Login thread will sleep until the specified window factor of time from last refresh to ticket's expiry has been reached, at which time it will try to renew the ticket.
Type: double Default: 0.8 Valid Values: Importance: low sasl.login.connect.timeout.ms
The (optional) value in milliseconds for the external authentication provider connection timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low sasl.login.read.timeout.ms
The (optional) value in milliseconds for the external authentication provider read timeout. Currently applies only to OAUTHBEARER.
Type: int Default: null Valid Values: Importance: low sasl.login.refresh.buffer.seconds
The amount of buffer time before credential expiration to maintain when refreshing a credential, in seconds. If a refresh would otherwise occur closer to expiration than the number of buffer seconds then the refresh will be moved up to maintain as much of the buffer time as possible. Legal values are between 0 and 3600 (1 hour); a default value of 300 (5 minutes) is used if no value is specified. This value and sasl.login.refresh.min.period.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 300 Valid Values: [0,...,3600] Importance: low sasl.login.refresh.min.period.seconds
The desired minimum time for the login refresh thread to wait before refreshing a credential, in seconds. Legal values are between 0 and 900 (15 minutes); a default value of 60 (1 minute) is used if no value is specified. This value and sasl.login.refresh.buffer.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.
Type: short Default: 60 Valid Values: [0,...,900] Importance: low sasl.login.refresh.window.factor
Login refresh thread will sleep until the specified window factor relative to the credential's lifetime has been reached, at which time it will try to refresh the credential. Legal values are between 0.5 (50%) and 1.0 (100%) inclusive; a default value of 0.8 (80%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.8 Valid Values: [0.5,...,1.0] Importance: low sasl.login.refresh.window.jitter
The maximum amount of random jitter relative to the credential's lifetime that is added to the login refresh thread's sleep time. Legal values are between 0 and 0.25 (25%) inclusive; a default value of 0.05 (5%) is used if no value is specified. Currently applies only to OAUTHBEARER.
Type: double Default: 0.05 Valid Values: [0.0,...,0.25] Importance: low sasl.login.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low sasl.login.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.
Type: long Default: 100 Valid Values: Importance: low sasl.oauthbearer.clock.skew.seconds
The (optional) value in seconds to allow for differences between the time of the OAuth/OIDC identity provider and the broker.
Type: int Default: 30 Valid Values: Importance: low sasl.oauthbearer.expected.audience
The (optional) comma-delimited setting for the broker to use to verify that the JWT was issued for one of the expected audiences. The JWT will be inspected for the standard OAuth "aud" claim and if this value is set, the broker will match the value from JWT's "aud" claim to see if there is an exact match. If there is no match, the broker will reject the JWT and authentication will fail.
Type: list Default: null Valid Values: Importance: low sasl.oauthbearer.expected.issuer
The (optional) setting for the broker to use to verify that the JWT was created by the expected issuer. The JWT will be inspected for the standard OAuth "iss" claim and if this value is set, the broker will match it exactly against what is in the JWT's "iss" claim. If there is no match, the broker will reject the JWT and authentication will fail.
Type: string Default: null Valid Values: Importance: low sasl.oauthbearer.header.urlencode
The (optional) setting to enable the OAuth client to URL-encode the client_id and client_secret in the authorization header in accordance with RFC6749, see here for more details. The default value is set to 'false' for backward compatibility
Type: boolean Default: false Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.refresh.ms
The (optional) value in milliseconds for the broker to wait between refreshing its JWKS (JSON Web Key Set) cache that contains the keys to verify the signature of the JWT.
Type: long Default: 3600000 (1 hour) Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms
The (optional) value in milliseconds for the maximum wait between attempts to retrieve the JWKS (JSON Web Key Set) from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 10000 (10 seconds) Valid Values: Importance: low sasl.oauthbearer.jwks.endpoint.retry.backoff.ms
The (optional) value in milliseconds for the initial wait between JWKS (JSON Web Key Set) retrieval attempts from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.
Type: long Default: 100 Valid Values: Importance: low sasl.oauthbearer.scope.claim.name
The OAuth claim for the scope is often named "scope", but this (optional) setting can provide a different name to use for the scope included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: scope Valid Values: Importance: low sasl.oauthbearer.sub.claim.name
The OAuth claim for the subject is often named "sub", but this (optional) setting can provide a different name to use for the subject included in the JWT payload's claims if the OAuth/OIDC provider uses a different name for that claim.
Type: string Default: sub Valid Values: Importance: low ssl.cipher.suites
A list of cipher suites. This is a named combination of authentication, encryption, MAC and key exchange algorithm used to negotiate the security settings for a network connection using TLS or SSL network protocol. By default all the available cipher suites are supported.
Type: list Default: null Valid Values: Importance: low ssl.endpoint.identification.algorithm
The endpoint identification algorithm to validate server hostname using server certificate.
Type: string Default: https Valid Values: Importance: low ssl.engine.factory.class
The class of type org.apache.kafka.common.security.auth.SslEngineFactory to provide SSLEngine objects. Default value is org.apache.kafka.common.security.ssl.DefaultSslEngineFactory. Alternatively, setting this to org.apache.kafka.common.security.ssl.CommonNameLoggingSslEngineFactory will log the common name of expired SSL certificates used by clients to authenticate at any of the brokers with log level INFO. Note that this will cause a tiny delay during establishment of new connections from mTLS clients to brokers due to the extra code for examining the certificate chain provided by the client. Note further that the implementation uses a custom truststore based on the standard Java truststore and thus might be considered a security risk due to not being as mature as the standard one.
Type: class Default: null Valid Values: Importance: low ssl.keymanager.algorithm
The algorithm used by key manager factory for SSL connections. Default value is the key manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: SunX509 Valid Values: Importance: low ssl.secure.random.implementation
The SecureRandom PRNG implementation to use for SSL cryptography operations.
Type: string Default: null Valid Values: Importance: low ssl.trustmanager.algorithm
The algorithm used by trust manager factory for SSL connections. Default value is the trust manager factory algorithm configured for the Java Virtual Machine.
Type: string Default: PKIX Valid Values: Importance: low name
Globally unique name to use for this connector.
Type: string Default: Valid Values: non-empty string without ISO control characters Importance: high connector.class
Name or alias of the class for this connector. Must be a subclass of org.apache.kafka.connect.connector.Connector. If the connector is org.apache.kafka.connect.file.FileStreamSinkConnector, you can either specify this full name, or use "FileStreamSink" or "FileStreamSinkConnector" to make the configuration a bit shorter
Type: string Default: Valid Values: Importance: high tasks.max
Maximum number of tasks to use for this connector.
Type: int Default: 1 Valid Values: [1,...] Importance: high tasks.max.enforce
(Deprecated) Whether to enforce that the tasks.max property is respected by the connector. By default, connectors that generate too many tasks will fail, and existing sets of tasks that exceed the tasks.max property will also be failed. If this property is set to false, then connectors will be allowed to generate more than the maximum number of tasks, and existing sets of tasks that exceed the tasks.max property will be allowed to run. This property is deprecated and will be removed in an upcoming major release.
Type: boolean Default: true Valid Values: Importance: low key.converter
Converter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the keys in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro.
Type: class Default: null Valid Values: A concrete subclass of org.apache.kafka.connect.storage.Converter, A class with a public, no-argument constructor Importance: low value.converter
Converter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the values in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro.
Type: class Default: null Valid Values: A concrete subclass of org.apache.kafka.connect.storage.Converter, A class with a public, no-argument constructor Importance: low header.converter
HeaderConverter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the header values in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro. By default, the SimpleHeaderConverter is used to serialize header values to strings and deserialize them by inferring the schemas.
Type: class Default: null Valid Values: A concrete subclass of org.apache.kafka.connect.storage.HeaderConverter, A class with a public, no-argument constructor Importance: low config.action.reload
The action that Connect should take on the connector when changes in external configuration providers result in a change in the connector's configuration properties. A value of 'none' indicates that Connect will do nothing. A value of 'restart' indicates that Connect should restart/reload the connector with the updated configuration properties.The restart may actually be scheduled in the future if the external configuration provider indicates that a configuration value will expire in the future.
Type: string Default: restart Valid Values: [none, restart] Importance: low transforms
Aliases for the transformations to be applied to records.
Type: list Default: "" Valid Values: non-null string, unique transformation aliases Importance: low predicates
Aliases for the predicates used by transformations.
Type: list Default: "" Valid Values: non-null string, unique predicate aliases Importance: low errors.retry.timeout
The maximum duration in milliseconds that a failed operation will be reattempted. The default is 0, which means no retries will be attempted. Use -1 for infinite retries.
Type: long Default: 0 Valid Values: Importance: medium errors.retry.delay.max.ms
The maximum duration in milliseconds between consecutive retry attempts. Jitter will be added to the delay once this limit is reached to prevent thundering herd issues.
Type: long Default: 60000 (1 minute) Valid Values: Importance: medium errors.tolerance
Behavior for tolerating errors during connector operation. 'none' is the default value and signals that any error will result in an immediate connector task failure; 'all' changes the behavior to skip over problematic records.
Type: string Default: none Valid Values: [none, all] Importance: medium errors.log.enable
If true, write each error and the details of the failed operation and problematic record to the Connect application log. This is 'false' by default, so that only errors that are not tolerated are reported.
Type: boolean Default: false Valid Values: Importance: medium errors.log.include.messages
Whether to include in the log the Connect record that resulted in a failure. For sink records, the topic, partition, offset, and timestamp will be logged. For source records, the key and value (and their schemas), all headers, and the timestamp, Kafka topic, Kafka partition, source partition, and source offset will be logged. This is 'false' by default, which will prevent record keys, values, and headers from being written to log files.
Type: boolean Default: false Valid Values: Importance: medium
MirrorMaker Source Configs
Below is the configuration of MirrorMaker 2 source connector for replicating topics.
config.properties.exclude
Topic config properties that should not be replicated. Supports comma-separated property names and regexes.
Type: list Default: follower\.replication\.throttled\.replicas,leader\.replication\.throttled\.replicas,message\.timestamp\.difference\.max\.ms,message\.timestamp\.type,unclean\.leader\.election\.enable,min\.insync\.replicas Valid Values: Importance: high topics
Topics to replicate. Supports comma-separated topic names and regexes.
Type: list Default: .* Valid Values: Importance: high topics.exclude
Excluded topics. Supports comma-separated topic names and regexes. Excludes take precedence over includes.
Type: list Default: mm2.*\.internal,.*\.replica,__.* Valid Values: Importance: high config.property.filter.class
ConfigPropertyFilter to use. Selects topic config properties to replicate.
Type: class Default: org.apache.kafka.connect.mirror.DefaultConfigPropertyFilter Valid Values: Importance: low consumer.poll.timeout.ms
Timeout when polling source cluster.
Type: long Default: 1000 (1 second) Valid Values: Importance: low emit.offset-syncs.enabled
Whether to store the new offset of the replicated records in offset-syncs topic or not. MirrorCheckpointConnector will not be able to sync group offsets or emit checkpoints if emit.checkpoints.enabled and/or sync.group.offsets.enabled are enabled while emit.offset-syncs.enabled is disabled.
Type: boolean Default: true Valid Values: Importance: low heartbeats.replication.enabled
Whether to replicate the heartbeats topics even when the topic filter does not include them. If set to true, heartbeats topics identified by the replication policy will always be replicated, regardless of the topic filter configuration. If set to false, heartbeats topics will only be replicated if the topic filter allows.
Type: boolean Default: true Valid Values: Importance: low offset-syncs.topic.location
The location (source/target) of the offset-syncs topic.
Type: string Default: source Valid Values: [source, target] Importance: low offset-syncs.topic.replication.factor
Replication factor for offset-syncs topic.
Type: short Default: 3 Valid Values: Importance: low offset.lag.max
How out-of-sync a remote partition can be before it is resynced.
Type: long Default: 100 Valid Values: Importance: low refresh.topics.enabled
Whether to periodically check for new topics and partitions.
Type: boolean Default: true Valid Values: Importance: low refresh.topics.interval.seconds
Frequency of topic refresh.
Type: long Default: 600 Valid Values: Importance: low replication.factor
Replication factor for newly created remote topics.
Type: int Default: 2 Valid Values: Importance: low sync.topic.acls.enabled
Whether to periodically configure remote topic ACLs to match their corresponding upstream topics.
Type: boolean Default: true Valid Values: Importance: low sync.topic.acls.interval.seconds
Frequency of topic ACL sync.
Type: long Default: 600 Valid Values: Importance: low sync.topic.configs.enabled
Whether to periodically configure remote topics to match their corresponding upstream topics.
Type: boolean Default: true Valid Values: Importance: low sync.topic.configs.interval.seconds
Frequency of topic config sync.
Type: long Default: 600 Valid Values: Importance: low topic.filter.class
TopicFilter to use. Selects topics to replicate.
Type: class Default: org.apache.kafka.connect.mirror.DefaultTopicFilter Valid Values: Importance: low
MirrorMaker Checkpoint Configs
Below is the configuration of MirrorMaker 2 checkpoint connector for emitting consumer offset checkpoints.
groups
Consumer groups to replicate. Supports comma-separated group IDs and regexes.
Type: list Default: .* Valid Values: Importance: high groups.exclude
Exclude groups. Supports comma-separated group IDs and regexes. Excludes take precedence over includes.
Type: list Default: console-consumer-.*,connect-.*,__.* Valid Values: Importance: high checkpoints.topic.replication.factor
Replication factor for checkpoints topic.
Type: short Default: 3 Valid Values: Importance: low consumer.poll.timeout.ms
Timeout when polling source cluster.
Type: long Default: 1000 (1 second) Valid Values: Importance: low emit.checkpoints.enabled
Whether to replicate consumer offsets to target cluster.
Type: boolean Default: true Valid Values: Importance: low emit.checkpoints.interval.seconds
Frequency of checkpoints.
Type: long Default: 60 Valid Values: Importance: low group.filter.class
GroupFilter to use. Selects consumer groups to replicate.
Type: class Default: org.apache.kafka.connect.mirror.DefaultGroupFilter Valid Values: Importance: low offset-syncs.topic.location
The location (source/target) of the offset-syncs topic.
Type: string Default: source Valid Values: [source, target] Importance: low refresh.groups.enabled
Whether to periodically check for new consumer groups.
Type: boolean Default: true Valid Values: Importance: low refresh.groups.interval.seconds
Frequency of group refresh.
Type: long Default: 600 Valid Values: Importance: low sync.group.offsets.enabled
Whether to periodically write the translated offsets to __consumer_offsets topic in target cluster, as long as no active consumers in that group are connected to the target cluster
Type: boolean Default: false Valid Values: Importance: low sync.group.offsets.interval.seconds
Frequency of consumer group offset sync.
Type: long Default: 60 Valid Values: Importance: low topic.filter.class
TopicFilter to use. Selects topics to replicate.
Type: class Default: org.apache.kafka.connect.mirror.DefaultTopicFilter Valid Values: Importance: low
MirrorMaker HeartBeat Configs
Below is the configuration of MirrorMaker 2 heartbeat connector for checking connectivity between connectors and clusters.
emit.heartbeats.enabled
Whether to emit heartbeats to target cluster.
Type: boolean Default: true Valid Values: Importance: low emit.heartbeats.interval.seconds
Frequency of heartbeats.
Type: long Default: 1 Valid Values: Importance: low heartbeats.topic.replication.factor
Replication factor for heartbeats topic.
Type: short Default: 3 Valid Values: Importance: low
System Properties
Kafka supports some configuration that can be enabled through Java system properties. System properties are usually set by passing the -D flag to the Java virtual machine in which Kafka components are running. Below are the supported system properties.
This system property is used to set the allowed URLs as SASL OAUTHBEARER token or jwks endpoints. This property accepts comma-separated list of URLs. By default the value is an empty list.
If users want to enable some URLs, users need to explicitly set the system property like below.
-Dorg.apache.kafka.sasl.oauthbearer.allowed.urls=https://www.example.com,file:///tmp/token
| Since: | 4.0.0 |
|---|---|
| Default Value: |
This system property is used to disable the problematic login modules usage in SASL JAAS configuration. This property accepts comma-separated list of loginModule names. By default com.sun.security.auth.module.JndiLoginModule loginModule is disabled.
If users want to enable JndiLoginModule, users need to explicitly reset the system property like below. We advise the users to validate configurations and only allow trusted JNDI configurations. For more details CVE-2023-25194.
-Dorg.apache.kafka.disallowed.login.modules=
To disable more loginModules, update the system property with comma-separated loginModule names. Make sure to explicitly add JndiLoginModule module name to the comma-separated list like below.
-Dorg.apache.kafka.disallowed.login.modules=com.sun.security.auth.module.JndiLoginModule,com.ibm.security.auth.module.LdapLoginModule,com.ibm.security.auth.module.Krb5LoginModule
| Since: | 3.4.0 |
|---|---|
| Default Value: | com.sun.security.auth.module.JndiLoginModule |
This system property controls the automatic loading of ConfigProvider implementations in Apache Kafka. ConfigProviders are used to dynamically supply configuration values from sources such as files, directories, or environment variables. This property accepts a comma-separated list of ConfigProvider names. By default, all built-in ConfigProviders are enabled, including FileConfigProvider , DirectoryConfigProvider , and EnvVarConfigProvider.
If users want to disable all automatic ConfigProviders, they need to explicitly set the system property as shown below. Disabling automatic ConfigProviders is recommended in environments where configuration data comes from untrusted sources or where increased security is required. For more details, see CVE-2024-31141.
-Dorg.apache.kafka.automatic.config.providers=none
To allow specific ConfigProviders, update the system property with a comma-separated list of fully qualified ConfigProvider class names. For example, to enable only the EnvVarConfigProvider , set the property as follows:
-Dorg.apache.kafka.automatic.config.providers=org.apache.kafka.common.config.provider.EnvVarConfigProvider
To use multiple ConfigProviders, include their names in a comma-separated list as shown below:
-Dorg.apache.kafka.automatic.config.providers=org.apache.kafka.common.config.provider.FileConfigProvider,org.apache.kafka.common.config.provider.EnvVarConfigProvider
| Since: | 3.8.0 |
|---|---|
| Default Value: | All built-in ConfigProviders are enabled |
Tiered Storage Configs
Below are the configuration properties for Tiered Storage.
log.local.retention.bytes
The maximum size of local log segments that can grow for a partition before it gets eligible for deletion. Default value is -2, it represents `log.retention.bytes` value to be used. The effective value should always be less than or equal to `log.retention.bytes` value.
Type: long Default: -2 Valid Values: [-2,...] Importance: medium log.local.retention.ms
The number of milliseconds to keep the local log segments before it gets eligible for deletion. Default value is -2, it represents `log.retention.ms` value is to be used. The effective value should always be less than or equal to `log.retention.ms` value.
Type: long Default: -2 Valid Values: [-2,...] Importance: medium remote.fetch.max.wait.ms
The maximum amount of time the server will wait before answering the remote fetch request
Type: int Default: 500 Valid Values: [1,...] Importance: medium remote.list.offsets.request.timeout.ms
The maximum amount of time the server will wait for the remote list offsets request to complete.
Type: long Default: 30000 (30 seconds) Valid Values: [1,...] Importance: medium remote.log.manager.copier.thread.pool.size
Size of the thread pool used in scheduling tasks to copy segments.
Type: int Default: 10 Valid Values: [1,...] Importance: medium remote.log.manager.copy.max.bytes.per.second
The maximum number of bytes that can be copied from local storage to remote storage per second. This is a global limit for all the partitions that are being copied from local storage to remote storage. The default value is Long.MAX_VALUE, which means there is no limit on the number of bytes that can be copied per second.
Type: long Default: 9223372036854775807 Valid Values: [1,...] Importance: medium remote.log.manager.copy.quota.window.num
The number of samples to retain in memory for remote copy quota management. The default value is 11, which means there are 10 whole windows + 1 current window.
Type: int Default: 11 Valid Values: [1,...] Importance: medium remote.log.manager.copy.quota.window.size.seconds
The time span of each sample for remote copy quota management. The default value is 1 second.
Type: int Default: 1 Valid Values: [1,...] Importance: medium remote.log.manager.expiration.thread.pool.size
Size of the thread pool used in scheduling tasks to clean up the expired remote log segments.
Type: int Default: 10 Valid Values: [1,...] Importance: medium remote.log.manager.fetch.max.bytes.per.second
The maximum number of bytes that can be fetched from remote storage to local storage per second. This is a global limit for all the partitions that are being fetched from remote storage to local storage. The default value is Long.MAX_VALUE, which means there is no limit on the number of bytes that can be fetched per second.
Type: long Default: 9223372036854775807 Valid Values: [1,...] Importance: medium remote.log.manager.fetch.quota.window.num
The number of samples to retain in memory for remote fetch quota management. The default value is 11, which means there are 10 whole windows + 1 current window.
Type: int Default: 11 Valid Values: [1,...] Importance: medium remote.log.manager.fetch.quota.window.size.seconds
The time span of each sample for remote fetch quota management. The default value is 1 second.
Type: int Default: 1 Valid Values: [1,...] Importance: medium remote.log.manager.thread.pool.size
Size of the thread pool used in scheduling follower tasks to read the highest-uploaded remote-offset for follower partitions.
Type: int Default: 2 Valid Values: [1,...] Importance: medium remote.log.metadata.manager.class.name
Fully qualified class name of `RemoteLogMetadataManager` implementation.
Type: string Default: org.apache.kafka.server.log.remote.metadata.storage.TopicBasedRemoteLogMetadataManager Valid Values: non-empty string Importance: medium remote.log.metadata.manager.class.path
Class path of the `RemoteLogMetadataManager` implementation. If specified, the RemoteLogMetadataManager implementation and its dependent libraries will be loaded by a dedicated classloader which searches this class path before the Kafka broker class path. The syntax of this parameter is same as the standard Java class path string.
Type: string Default: null Valid Values: Importance: medium remote.log.metadata.manager.impl.prefix
Prefix used for properties to be passed to RemoteLogMetadataManager implementation. For example this value can be `rlmm.config.`.
Type: string Default: rlmm.config. Valid Values: non-empty string Importance: medium remote.log.metadata.manager.listener.name
Listener name of the local broker to which it should get connected if needed by RemoteLogMetadataManager implementation.
Type: string Default: null Valid Values: non-empty string Importance: medium remote.log.reader.max.pending.tasks
Maximum remote log reader thread pool task queue size. If the task queue is full, fetch requests are served with an error.
Type: int Default: 100 Valid Values: [1,...] Importance: medium remote.log.reader.threads
Size of the thread pool that is allocated for handling remote log reads.
Type: int Default: 10 Valid Values: [1,...] Importance: medium remote.log.storage.manager.class.name
Fully qualified class name of `RemoteStorageManager` implementation.
Type: string Default: null Valid Values: non-empty string Importance: medium remote.log.storage.manager.class.path
Class path of the `RemoteStorageManager` implementation. If specified, the RemoteStorageManager implementation and its dependent libraries will be loaded by a dedicated classloader which searches this class path before the Kafka broker class path. The syntax of this parameter is same as the standard Java class path string.
Type: string Default: null Valid Values: Importance: medium remote.log.storage.manager.impl.prefix
Prefix used for properties to be passed to RemoteStorageManager implementation. For example this value can be `rsm.config.`.
Type: string Default: rsm.config. Valid Values: non-empty string Importance: medium remote.log.storage.system.enable
Whether to enable tiered storage functionality in a broker or not. When it is true broker starts all the services required for the tiered storage functionality.
Type: boolean Default: false Valid Values: Importance: medium remote.log.index.file.cache.total.size.bytes
The total size of the space allocated to store index files fetched from remote storage in the local storage.
Type: long Default: 1073741824 (1 gibibyte) Valid Values: [1,...] Importance: low remote.log.manager.task.interval.ms
Interval at which remote log manager runs the scheduled tasks like copy segments, and clean up remote log segments.
Type: long Default: 30000 (30 seconds) Valid Values: [1,...] Importance: low remote.log.metadata.custom.metadata.max.bytes
The maximum size of custom metadata in bytes that the broker should accept from a remote storage plugin. If custom metadata exceeds this limit, the updated segment metadata will not be stored, the copied data will be attempted to delete, and the remote copying task for this topic-partition will stop with an error.
Type: int Default: 128 Valid Values: [0,...] Importance: low
remote.log.metadata.consume.wait.ms
The amount of time in milliseconds to wait for the local consumer to receive the published event.
Type: long Default: 120000 (2 minutes) Valid Values: [0,...] Importance: low remote.log.metadata.initialization.retry.interval.ms
The retry interval in milliseconds for retrying RemoteLogMetadataManager resources initialization again.
Type: long Default: 100 Valid Values: [0,...] Importance: low remote.log.metadata.initialization.retry.max.timeout.ms
The maximum amount of time in milliseconds for retrying RemoteLogMetadataManager resources initialization. When total retry intervals reach this timeout, initialization is considered as failed and broker starts shutting down.
Type: long Default: 120000 (2 minutes) Valid Values: [0,...] Importance: low remote.log.metadata.topic.num.partitions
The number of partitions for remote log metadata topic.
Type: int Default: 50 Valid Values: [1,...] Importance: low remote.log.metadata.topic.replication.factor
Replication factor of remote log metadata topic.
Type: short Default: 3 Valid Values: [1,...] Importance: low remote.log.metadata.topic.retention.ms
Retention of remote log metadata topic in milliseconds. Default: -1, that means unlimited. Users can configure this value based on their use cases. To avoid any data loss, this value should be more than the maximum retention period of any topic enabled with tiered storage in the cluster.
Type: long Default: -1 Valid Values: Importance: low
Configuration Providers
Use configuration providers to load configuration data from external sources. This might include sensitive information, such as passwords, API keys, or other credentials.
You have the following options:
- Use a custom provider by creating a class implementing the
ConfigProviderinterface and packaging it into a JAR file. - Use a built-in provider:
To use a configuration provider, specify it in your configuration using the config.providers property.
Using Configuration Providers
Configuration providers allow you to pass parameters and retrieve configuration data from various sources.
To specify configuration providers, you use a comma-separated list of aliases and the fully-qualified class names that implement the configuration providers:
config.providers=provider1,provider2
config.providers.provider1.class=com.example.Provider1
config.providers.provider2.class=com.example.Provider2
Each provider can have its own set of parameters, which are passed in a specific format:
config.providers.<provider_alias>.param.<name>=<value>
The ConfigProvider interface serves as a base for all configuration providers. Custom implementations of this interface can be created to retrieve configuration data from various sources. You can package the implementation as a JAR file, add the JAR to your classpath, and reference the provider’s class in your configuration.
Example custom provider configuration
config.providers=customProvider
config.providers.customProvider.class=com.example.customProvider
config.providers.customProvider.param.param1=value1
config.providers.customProvider.param.param2=value2
DirectoryConfigProvider
The DirectoryConfigProvider retrieves configuration data from files stored in a specified directory.
Each file represents a key, and its content is the value. This provider is useful for loading multiple configuration files and for organizing configuration data into separate files.
To restrict the files that the DirectoryConfigProvider can access, use the allowed.paths parameter. This parameter accepts a comma-separated list of paths that the provider is allowed to access. If not set, all paths are allowed.
ExampleDirectoryConfigProvider configuration
config.providers=dirProvider
config.providers.dirProvider.class=org.apache.kafka.common.config.provider.DirectoryConfigProvider
config.providers.dirProvider.param.allowed.paths=/path/to/dir1,/path/to/dir2
To reference a value supplied by the DirectoryConfigProvider, use the correct placeholder syntax:
${dirProvider:<path_to_file>:<file_name>}
EnvVarConfigProvider
The EnvVarConfigProvider retrieves configuration data from environment variables.
No specific parameters are required, as it reads directly from the specified environment variables.
This provider is useful for configuring applications running in containers, for example, to load certificates or JAAS configuration from environment variables mapped from secrets.
To restrict which environment variables the EnvVarConfigProvider can access, use the allowlist.pattern parameter. This parameter accepts a regular expression that environment variable names must match to be used by the provider.
ExampleEnvVarConfigProvider configuration
config.providers=envVarProvider
config.providers.envVarProvider.class=org.apache.kafka.common.config.provider.EnvVarConfigProvider
config.providers.envVarProvider.param.allowlist.pattern=^MY_ENVAR1_.*
To reference a value supplied by the EnvVarConfigProvider, use the correct placeholder syntax:
${envVarProvider:<enVar_name>}
FileConfigProvider
The FileConfigProvider retrieves configuration data from a single properties file.
This provider is useful for loading configuration data from mounted files.
To restrict the file paths that the FileConfigProvider can access, use the allowed.paths parameter. This parameter accepts a comma-separated list of paths that the provider is allowed to access. If not set, all paths are allowed.
ExampleFileConfigProvider configuration
config.providers=fileProvider
config.providers.fileProvider.class=org.apache.kafka.common.config.provider.FileConfigProvider
config.providers.fileProvider.param.allowed.paths=/path/to/config1,/path/to/config2
To reference a value supplied by the FileConfigProvider, use the correct placeholder syntax:
${fileProvider:<path_and_filename>:<property>}
Example: Referencing files
Here’s an example that uses a file configuration provider with Kafka Connect to provide authentication credentials to a database for a connector.
First, create a connector-credentials.properties configuration file with the following credentials:
dbUsername=my-username
dbPassword=my-password
Specify a FileConfigProvider in the Kafka Connect configuration:
Example Kafka Connect configuration with aFileConfigProvider
config.providers=fileProvider
config.providers.fileProvider.class=org.apache.kafka.common.config.provider.FileConfigProvider
Next, reference the properties from the file in the connector configuration.
Example connector configuration referencing file properties
database.user=${fileProvider:/path/to/connector-credentials.properties:dbUsername}
database.password=${fileProvider:/path/to/connector-credentials.properties:dbPassword}
At runtime, the configuration provider reads and extracts the values from the properties file.