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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:
broker.idlog.dirszookeeper.connectTopic-level configurations and defaults are discussed in more detail below.zookeeper.connect
Specifies the ZooKeeper connection string in the form
hostname:portwhere host and port are the host and port of a ZooKeeper server. To allow connecting through other ZooKeeper nodes when that ZooKeeper machine is down you can also specify multiple hosts in the formhostname1:port1,hostname2:port2,hostname3:port3.
The server can also have a ZooKeeper chroot path as part of its ZooKeeper connection string which puts its data under some path in the global ZooKeeper namespace. For example to give a chroot path of/chroot/pathyou would give the connection string ashostname1:port1,hostname2:port2,hostname3:port3/chroot/path.Type: string Default: Valid Values: Importance: high Update Mode: read-only advertised.host.name
DEPRECATED: only used when
advertised.listenersorlistenersare not set. Useadvertised.listenersinstead.
Hostname to publish to ZooKeeper for clients to use. In IaaS environments, this may need to be different from the interface to which the broker binds. If this is not set, it will use the value forhost.nameif configured. Otherwise it will use the value returned from java.net.InetAddress.getCanonicalHostName().Type: string Default: null Valid Values: Importance: high Update Mode: read-only advertised.listeners
Listeners to publish to ZooKeeper for clients to use, if different than the
listenersconfig property. 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. Unlikelistenersit is not valid to advertise the 0.0.0.0 meta-address.Type: string Default: null Valid Values: Importance: high Update Mode: per-broker advertised.port
DEPRECATED: only used when
advertised.listenersorlistenersare not set. Useadvertised.listenersinstead.
The port to publish to ZooKeeper for clients to use. In IaaS environments, this may need to be different from the port to which the broker binds. If this is not set, it will publish the same port that the broker binds to.Type: int 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 imbalance exceeds `leader.imbalance.per.broker.percentage`, 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. If unset, a unique broker id will be generated.To avoid conflicts between zookeeper generated broker id's and user configured broker id's, generated broker ids start from reserved.broker.max.id + 1.
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: Importance: high Update Mode: cluster-wide control.plane.listener.name
Name of listener used for communication between controller and brokers. Broker will use the control.plane.listener.name to locate the endpoint in listeners list, to listen for connections from the controller. For example, if a broker's config is :
listeners = INTERNAL://192.1.1.8:9092, EXTERNAL://10.1.1.5:9093, CONTROLLER://192.1.1.8:9094
listener.security.protocol.map = INTERNAL:PLAINTEXT, EXTERNAL:SSL, CONTROLLER:SSL
control.plane.listener.name = CONTROLLER
On startup, the broker will start listening on "192.1.1.8:9094" with security protocol "SSL".
On controller side, when it discovers a broker's published endpoints through zookeeper, it will use the control.plane.listener.name to find the endpoint, which it will use to establish connection to the broker.
For example, if the broker's published endpoints on zookeeper are :
"endpoints" : ["INTERNAL://broker1.example.com:9092","EXTERNAL://broker1.example.com:9093","CONTROLLER://broker1.example.com:9094"]
and the controller's config is :
listener.security.protocol.map = INTERNAL:PLAINTEXT, EXTERNAL:SSL, CONTROLLER:SSL
control.plane.listener.name = CONTROLLER
then controller will use "broker1.example.com:9094" with security protocol "SSL" to connect to the broker.
If not explicitly configured, the default value will be null and there will be no dedicated endpoints for controller connections.Type: string Default: null Valid Values: 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 host.name
DEPRECATED: only used when
listenersis not set. Uselistenersinstead.
hostname of broker. If this is set, it will only bind to this address. If this is not set, it will bind to all interfacesType: string Default: "" Valid Values: 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: Importance: high Update Mode: read-only leader.imbalance.per.broker.percentage
The ratio of leader imbalance allowed per broker. The controller would trigger a leader balance if it goes above this value per broker. The value is specified in percentage.
Type: int Default: 10 Valid Values: 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.map must also be set.
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://:9091
CLIENT://0.0.0.0:9092,REPLICATION://localhost:9093Type: string Default: null 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
The directories in which the log data is kept. 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: [14,...] Importance: high Update Mode: cluster-wide log.segment.delete.delay.ms
The amount of time to wait before deleting a file from the filesystem
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 min.insync.replicas
When a producer sets acks to "all" (or "-1"), min.insync.replicas 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 NotEnoughReplicas or NotEnoughReplicasAfterAppend).
When used together, min.insync.replicas and acks allow you to enforce greater durability guarantees. A typical scenario would be to create a topic with a replication factor of 3, set min.insync.replicas to 2, and produce with acks of "all". This will ensure that the producer raises an exception if a majority of replicas do not receive a write.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
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: 1 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
Type: int Default: null Valid Values: Importance: high Update Mode: read-only num.replica.fetchers
Number of fetcher threads used to replicate messages from a source broker. Increasing this value can increase the degree of I/O parallelism in the follower broker.
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.required.acks
The required acks before the commit can be accepted. In general, the default (-1) should not be overridden
Type: short Default: -1 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.
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 offsets 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
After a consumer group loses all its consumers (i.e. becomes empty) its offsets will be kept for this retention period before getting discarded. For standalone consumers (using manual assignment), offsets will be expired after the time of last commit plus this 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 port
DEPRECATED: only used when
listenersis not set. Uselistenersinstead.
the port to listen and accept connections onType: int Default: 9092 Valid Values: 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 quota.consumer.default
DEPRECATED: Used only when dynamic default quotas are not configured for
Type: long Default: 9223372036854775807 Valid Values: [1,...] Importance: high Update Mode: read-only quota.producer.default
DEPRECATED: Used only when dynamic default quotas are not configured for
, or Type: long Default: 9223372036854775807 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 replicaMaxWaitTimeMs
Type: int Default: 1 Valid Values: Importance: high Update Mode: read-only replica.fetch.wait.max.ms
max 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 leaders 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
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 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
Overridden min.insync.replicas config for the transaction topic.
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. This setting also influences producer id expiration - producer ids are expired once this time has elapsed after the last write with the given producer id. Note that producer ids may expire sooner if the last write from the producer id is deleted due to the topic's retention settings.
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
Type: boolean Default: false Valid Values: Importance: high Update Mode: cluster-wide zookeeper.connection.timeout.ms
The max time that the client waits to establish a connection to zookeeper. If not set, the value in zookeeper.session.timeout.ms is used
Type: int Default: null Valid Values: Importance: high Update Mode: read-only zookeeper.max.in.flight.requests
The maximum number of unacknowledged requests the client will send to Zookeeper before blocking.
Type: int Default: 10 Valid Values: [1,...] Importance: high Update Mode: read-only zookeeper.session.timeout.ms
Zookeeper session timeout
Type: int Default: 18000 (18 seconds) Valid Values: Importance: high Update Mode: read-only zookeeper.set.acl
Set client to use secure ACLs
Type: boolean Default: false Valid Values: Importance: high Update Mode: read-only broker.id.generation.enable
Enable automatic broker id generation on the server. When enabled the value configured for reserved.broker.max.id should be reviewed.
Type: boolean Default: true 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-1d`
Type: string Default: null Valid Values: Importance: medium Update Mode: read-only 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 controlled.shutdown.max.retries
Controlled shutdown can fail for multiple reasons. This determines the number of retries when such failure happens
Type: int Default: 3 Valid Values: Importance: medium Update Mode: read-only controlled.shutdown.retry.backoff.ms
Before each retry, the system needs time to recover from the state that caused the previous failure (Controller fail over, replica lag etc). This config determines the amount of time to wait before retrying.
Type: long Default: 5000 (5 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
default replication factors for automatically created topics
Type: int Default: 1 Valid Values: Importance: medium Update Mode: read-only delegation.token.expiry.time.ms
The token validity time in miliseconds 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.master.key
Master/secret key to generate and verify delegation tokens. Same key must be configured across all the brokers. 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 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 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.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 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 inter.broker.protocol.version
Specify which version of the inter-broker protocol will be used.
This is typically bumped after all brokers were upgraded to a new version.
Example of some valid values are: 0.8.0, 0.8.1, 0.8.1.1, 0.8.2, 0.8.2.0, 0.8.2.1, 0.9.0.0, 0.9.0.1 Check ApiVersion for the full list.Type: string Default: 2.6-IV0 Valid Values: [0.8.0, 0.8.1, 0.8.2, 0.9.0, 0.10.0-IV0, 0.10.0-IV1, 0.10.1-IV0, 0.10.1-IV1, 0.10.1-IV2, 0.10.2-IV0, 0.11.0-IV0, 0.11.0-IV1, 0.11.0-IV2, 1.0-IV0, 1.1-IV0, 2.0-IV0, 2.0-IV1, 2.1-IV0, 2.1-IV1, 2.1-IV2, 2.2-IV0, 2.2-IV1, 2.3-IV0, 2.3-IV1, 2.4-IV0, 2.4-IV1, 2.5-IV0, 2.6-IV0] 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
How long are delete records retained?
Type: long Default: 86400000 (1 day) Valid Values: 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: 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: 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: 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. Valid policies are: "delete" and "compact"
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.message.format.version
Specify the message format version the broker will use to append messages to the logs. The value should be a valid ApiVersion. Some examples are: 0.8.2, 0.9.0.0, 0.10.0, check ApiVersion for more details. By setting a particular message format version, the user is certifying that all the existing messages on disk are smaller or equal than the specified version. Setting this value incorrectly will cause consumers with older versions to break as they will receive messages with a format that they don't understand.
Type: string Default: 2.6-IV0 Valid Values: [0.8.0, 0.8.1, 0.8.2, 0.9.0, 0.10.0-IV0, 0.10.0-IV1, 0.10.1-IV0, 0.10.1-IV1, 0.10.1-IV2, 0.10.2-IV0, 0.11.0-IV0, 0.11.0-IV1, 0.11.0-IV2, 1.0-IV0, 1.1-IV0, 2.0-IV0, 2.0-IV1, 2.1-IV0, 2.1-IV1, 2.1-IV2, 2.2-IV0, 2.2-IV1, 2.3-IV0, 2.3-IV1, 2.4-IV0, 2.4-IV1, 2.5-IV0, 2.6-IV0] Importance: medium Update Mode: read-only log.message.timestamp.difference.max.ms
The maximum difference allowed between the timestamp when a broker receives a message and the timestamp specified in the message. If log.message.timestamp.type=CreateTime, a message will be rejected if the difference in timestamp exceeds this threshold. This configuration is ignored if log.message.timestamp.type=LogAppendTime.The maximum timestamp difference allowed should be no greater than log.retention.ms to avoid unnecessarily frequent log rolling.
Type: long Default: 9223372036854775807 Valid Values: 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 `CreateTime` or `LogAppendTime`
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.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. 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 incremental fetch sessions that we will maintain.
Type: int Default: 1000 Valid Values: [0,...] 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 password.encoder.old.secret
The old secret that was used for encoding dynamically configured passwords. This is required only when the secret is updated. If specified, all dynamically encoded passwords are decoded using this old secret and re-encoded using password.encoder.secret when broker starts up.
Type: password Default: null Valid Values: Importance: medium Update Mode: read-only password.encoder.secret
The secret used for encoding dynamically configured passwords for this broker.
Type: password Default: null Valid Values: 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. This config also supports the deprecated PrincipalBuilder interface which was previously used for client authentication over SSL. 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.Type: class Default: null 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 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 reserved.broker.max.id
Max number that can be used for a broker.id
Type: int Default: 1000 Valid Values: [0,...] 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 of KafkaPrincipalBuilder is provided by the
principal.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.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 security.inter.broker.protocol
Security protocol used to communicate between brokers. Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL. It is an error to set this and inter.broker.listener.name properties at the same time.
Type: string Default: PLAINTEXT Valid Values: 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 requested , 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' when running with Java 11 or newer, 'TLSv1.2' otherwise. With the default value for Java 11, 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 cases. Also see the config documentation for `ssl.protocol`.
Type: list Default: TLSv1.2 Valid Values: Importance: medium Update Mode: per-broker ssl.key.password
The password of the private key in the key store file. This is optional for client.
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.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.
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.
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' when running with Java 11 or newer, 'TLSv1.2' otherwise. This value should be fine for most use cases. Allowed values in recent JVMs are 'TLSv1.2' and 'TLSv1.3'. 'TLS', 'TLSv1.1', 'SSL', 'SSLv2' and 'SSLv3' may be supported in older JVMs, but their usage is discouraged due to known security vulnerabilities. With the default value for this config and 'ssl.enabled.protocols', clients will downgrade to 'TLSv1.2' if the server does not support 'TLSv1.3'. If this config is set to 'TLSv1.2', 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: TLSv1.2 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.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 access to the truststore is still available, but integrity checking is disabled.
Type: password Default: null Valid Values: Importance: medium Update Mode: per-broker ssl.truststore.type
The file format of the trust store file.
Type: string Default: JKS Valid Values: Importance: medium Update Mode: per-broker zookeeper.clientCnxnSocket
Typically set to
org.apache.zookeeper.ClientCnxnSocketNettywhen using TLS connectivity to ZooKeeper. Overrides any explicit value set via the same-namedzookeeper.clientCnxnSocketsystem property.Type: string Default: null Valid Values: Importance: medium Update Mode: read-only zookeeper.ssl.client.enable
Set client to use TLS when connecting to ZooKeeper. An explicit value overrides any value set via the
zookeeper.client.securesystem property (note the different name). Defaults to false if neither is set; when true,zookeeper.clientCnxnSocketmust be set (typically toorg.apache.zookeeper.ClientCnxnSocketNetty); other values to set may includezookeeper.ssl.cipher.suites,zookeeper.ssl.crl.enable,zookeeper.ssl.enabled.protocols,zookeeper.ssl.endpoint.identification.algorithm,zookeeper.ssl.keystore.location,zookeeper.ssl.keystore.password,zookeeper.ssl.keystore.type,zookeeper.ssl.ocsp.enable,zookeeper.ssl.protocol,zookeeper.ssl.truststore.location,zookeeper.ssl.truststore.password,zookeeper.ssl.truststore.typeType: boolean Default: false Valid Values: Importance: medium Update Mode: read-only zookeeper.ssl.keystore.location
Keystore location when using a client-side certificate with TLS connectivity to ZooKeeper. Overrides any explicit value set via the
zookeeper.ssl.keyStore.locationsystem property (note the camelCase).Type: string Default: null Valid Values: Importance: medium Update Mode: read-only zookeeper.ssl.keystore.password
Keystore password when using a client-side certificate with TLS connectivity to ZooKeeper. Overrides any explicit value set via the
zookeeper.ssl.keyStore.passwordsystem property (note the camelCase). Note that ZooKeeper does not support a key password different from the keystore password, so be sure to set the key password in the keystore to be identical to the keystore password; otherwise the connection attempt to Zookeeper will fail.Type: password Default: null Valid Values: Importance: medium Update Mode: read-only zookeeper.ssl.keystore.type
Keystore type when using a client-side certificate with TLS connectivity to ZooKeeper. Overrides any explicit value set via the
zookeeper.ssl.keyStore.typesystem property (note the camelCase). The default value ofnullmeans the type will be auto-detected based on the filename extension of the keystore.Type: string Default: null Valid Values: Importance: medium Update Mode: read-only zookeeper.ssl.truststore.location
Truststore location when using TLS connectivity to ZooKeeper. Overrides any explicit value set via the
zookeeper.ssl.trustStore.locationsystem property (note the camelCase).Type: string Default: null Valid Values: Importance: medium Update Mode: read-only zookeeper.ssl.truststore.password
Truststore password when using TLS connectivity to ZooKeeper. Overrides any explicit value set via the
zookeeper.ssl.trustStore.passwordsystem property (note the camelCase).Type: password Default: null Valid Values: Importance: medium Update Mode: read-only zookeeper.ssl.truststore.type
Truststore type when using TLS connectivity to ZooKeeper. Overrides any explicit value set via the
zookeeper.ssl.trustStore.typesystem property (note the camelCase). The default value ofnullmeans the type will be auto-detected based on the filename extension of the truststore.Type: string Default: null Valid Values: Importance: medium Update Mode: read-only 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.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 sorg.apache.kafka.server.authorizer.Authorizer interface, which is used by the broker for authorization. This config also supports authorizers that implement the deprecated kafka.security.auth.Authorizer trait which was previously used for authorization.
Type: string Default: "" Valid Values: 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. By default,
or quotas stored in ZooKeeper are applied. 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 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.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 name
listener.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).Type: string Default: PLAINTEXT:PLAINTEXT,SSL:SSL,SASL_PLAINTEXT:SASL_PLAINTEXT,SASL_SSL:SASL_SSL Valid Values: Importance: low Update Mode: per-broker log.message.downconversion.enable
This configuration controls whether down-conversion of message formats is enabled to satisfy consume requests. When set to
false, broker will not perform down-conversion for consumers expecting an older message format. The broker responds withUNSUPPORTED_VERSIONerror for consume requests from such older clients. This configurationdoes not apply to any message format conversion that might be required for replication to followers.Type: boolean Default: true Valid Values: Importance: low Update Mode: cluster-wide 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. The JmxReporter is always included to register JMX statistics.Type: list Default: "" 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.
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 password.encoder.cipher.algorithm
The Cipher algorithm used for encoding dynamically configured passwords.
Type: string Default: AES/CBC/PKCS5Padding Valid Values: Importance: low Update Mode: read-only password.encoder.iterations
The iteration count used for encoding dynamically configured passwords.
Type: int Default: 4096 Valid Values: [1024,...] Importance: low Update Mode: read-only password.encoder.key.length
The key length used for encoding dynamically configured passwords.
Type: int Default: 128 Valid Values: [8,...] Importance: low Update Mode: read-only password.encoder.keyfactory.algorithm
The SecretKeyFactory algorithm used for encoding dynamically configured passwords. Default is PBKDF2WithHmacSHA512 if available and PBKDF2WithHmacSHA1 otherwise.
Type: string Default: null Valid Values: Importance: low Update Mode: read-only 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 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 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.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
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 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.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 zookeeper.ssl.cipher.suites
Specifies the enabled cipher suites to be used in ZooKeeper TLS negotiation (csv). Overrides any explicit value set via the
zookeeper.ssl.ciphersuitessystem property (note the single word "ciphersuites"). The default value ofnullmeans the list of enabled cipher suites is determined by the Java runtime being used.Type: list Default: null Valid Values: Importance: low Update Mode: read-only zookeeper.ssl.crl.enable
Specifies whether to enable Certificate Revocation List in the ZooKeeper TLS protocols. Overrides any explicit value set via the
zookeeper.ssl.crlsystem property (note the shorter name).Type: boolean Default: false Valid Values: Importance: low Update Mode: read-only zookeeper.ssl.enabled.protocols
Specifies the enabled protocol(s) in ZooKeeper TLS negotiation (csv). Overrides any explicit value set via the
zookeeper.ssl.enabledProtocolssystem property (note the camelCase). The default value ofnullmeans the enabled protocol will be the value of thezookeeper.ssl.protocolconfiguration property.Type: list Default: null Valid Values: Importance: low Update Mode: read-only zookeeper.ssl.endpoint.identification.algorithm
Specifies whether to enable hostname verification in the ZooKeeper TLS negotiation process, with (case-insensitively) "https" meaning ZooKeeper hostname verification is enabled and an explicit blank value meaning it is disabled (disabling it is only recommended for testing purposes). An explicit value overrides any "true" or "false" value set via the
zookeeper.ssl.hostnameVerificationsystem property (note the different name and values; true implies https and false implies blank).Type: string Default: HTTPS Valid Values: Importance: low Update Mode: read-only zookeeper.ssl.ocsp.enable
Specifies whether to enable Online Certificate Status Protocol in the ZooKeeper TLS protocols. Overrides any explicit value set via the
zookeeper.ssl.ocspsystem property (note the shorter name).Type: boolean Default: false Valid Values: Importance: low Update Mode: read-only zookeeper.ssl.protocol
Specifies the protocol to be used in ZooKeeper TLS negotiation. An explicit value overrides any value set via the same-named
zookeeper.ssl.protocolsystem property.Type: string Default: TLSv1.2 Valid Values: Importance: low Update Mode: read-only zookeeper.sync.time.ms
How far a ZK follower can be behind a ZK leader
Type: int Default: 2000 (2 seconds) Valid Values: 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 ZooKeeper
- Dynamic cluster-wide default config stored in ZooKeeper
- Static broker config from
server.properties - Kafka default, see broker configs
Updating Password Configs Dynamically
Password config values that are dynamically updated are encrypted before storing in ZooKeeper. The broker config password.encoder.secret must be configured in server.properties to enable dynamic update of password configs. The secret may be different on different brokers.
The secret used for password encoding may be rotated with a rolling restart of brokers. The old secret used for encoding passwords currently in ZooKeeper must be provided in the static broker config password.encoder.old.secret and the new secret must be provided in password.encoder.secret. All dynamic password configs stored in ZooKeeper will be re-encoded with the new secret when the broker starts up.
In Kafka 1.1.x, all dynamically updated password configs must be provided in every alter request when updating configs using kafka-configs.sh even if the password config is not being altered. This constraint will be removed in a future release.
Updating Password Configs in ZooKeeper Before Starting Brokers
From Kafka 2.0.0 onwards, kafka-configs.sh enables dynamic broker configs to be updated using ZooKeeper before starting brokers for bootstrapping. This enables all password configs to be stored in encrypted form, avoiding the need for clear passwords in server.properties. The broker config password.encoder.secret must also be specified if any password configs are included in the alter command. Additional encryption parameters may also be specified. Password encoder configs will not be persisted in ZooKeeper. For example, to store SSL key password for listener INTERNAL on broker 0:
> bin/kafka-configs.sh --zookeeper localhost:2182 --zk-tls-config-file zk_tls_config.properties --entity-type brokers --entity-name 0 --alter --add-config
'listener.name.internal.ssl.key.password=key-password,password.encoder.secret=secret,password.encoder.iterations=8192'
The configuration listener.name.internal.ssl.key.password will be persisted in ZooKeeper in encrypted form using the provided encoder configs. The encoder secret and iterations are not persisted in ZooKeeper.
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.typelog.message.timestamp.difference.max.ms
From Kafka version 2.0.0 onwards, unclean leader election is automatically enabled by the controller when the config unclean.leader.election.enable is dynamically updated. In Kafka version 1.1.x, changes to unclean.leader.election.enable take effect only when a new controller is elected. Controller re-election may be forced by running:
> bin/zookeeper-shell.sh localhost
rmr /controller
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.threads
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 inter.broker.security.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
A string that is either "delete" or "compact" or both. This string designates the retention policy to use on old log segments. The default policy ("delete") will discard old segments when their retention time or size limit has been reached. The "compact" setting will enable log compaction on the topic.
Type: list Default: delete Valid Values: [compact, delete] Server Default Property: log.cleanup.policy 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 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: [0,...] 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: follower.replication.throttled.replicas 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: leader.replication.throttled.replicas 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.format.version
Specify the message format version the broker will use to append messages to the logs. The value should be a valid ApiVersion. Some examples are: 0.8.2, 0.9.0.0, 0.10.0, check ApiVersion for more details. By setting a particular message format version, the user is certifying that all the existing messages on disk are smaller or equal than the specified version. Setting this value incorrectly will cause consumers with older versions to break as they will receive messages with a format that they don't understand.
Type: string Default: 2.6-IV0 Valid Values: [0.8.0, 0.8.1, 0.8.2, 0.9.0, 0.10.0-IV0, 0.10.0-IV1, 0.10.1-IV0, 0.10.1-IV1, 0.10.1-IV2, 0.10.2-IV0, 0.11.0-IV0, 0.11.0-IV1, 0.11.0-IV2, 1.0-IV0, 1.1-IV0, 2.0-IV0, 2.0-IV1, 2.1-IV0, 2.1-IV1, 2.1-IV2, 2.2-IV0, 2.2-IV1, 2.3-IV0, 2.3-IV1, 2.4-IV0, 2.4-IV1, 2.5-IV0, 2.6-IV0] Server Default Property: log.message.format.version Importance: medium message.timestamp.difference.max.ms
The maximum difference allowed between the timestamp when a broker receives a message and the timestamp specified in the message. If message.timestamp.type=CreateTime, a message will be rejected if the difference in timestamp exceeds this threshold. This configuration is ignored if message.timestamp.type=LogAppendTime.
Type: long Default: 9223372036854775807 Valid Values: [0,...] Server Default Property: log.message.timestamp.difference.max.ms Importance: medium message.timestamp.type
Define whether the timestamp in the message is message create time or log append time. The value should be either `CreateTime` or `LogAppendTime`
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 NotEnoughReplicas or NotEnoughReplicasAfterAppend).
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 the producer raises an exception if a majority of replicas do not receive a write.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 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.
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.
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: [0,...] 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.
Type: boolean Default: false Valid Values: Server Default Property: unclean.leader.election.enable Importance: medium message.downconversion.enable
This configuration controls whether down-conversion of message formats is enabled to satisfy consume requests. When set to
false, broker will not perform down-conversion for consumers expecting an older message format. The broker responds withUNSUPPORTED_VERSIONerror for consume requests from such older clients. This configurationdoes not apply to any message format conversion that might be required for replication to followers.Type: boolean Default: true Valid Values: Server Default Property: log.message.downconversion.enable Importance: low
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 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.
Type: string Default: 1 Valid Values: [all, -1, 0, 1] Importance: high bootstrap.servers
A list of host/port pairs to use for establishing the initial connection to the Kafka cluster. The client will make use of all servers irrespective of which servers are specified here for bootstrapping—this list only impacts the initial hosts used to discover the full set of servers. This list should be in the form
host1:port1,host2:port2,.... Since these servers are just used for the initial connection to discover the full cluster membership (which may change dynamically), this list need not contain the full set of servers (you may want more than one, though, in case a server is down).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: 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. Allowing retries without setting
max.in.flight.requests.per.connectionto 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. Note additionally that produce requests will be failed before the number of retries has been exhausted if the timeout configured bydelivery.timeout.msexpires first before successful acknowledgement. Users should generally prefer to leave this config unset and instead usedelivery.timeout.msto control retry behavior.Type: int Default: 2147483647 Valid Values: [0,...,2147483647] Importance: high ssl.key.password
The password of the private key in the key store file. This is optional for client.
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.
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 access to the truststore is still available, but integrity checking is disabled.
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.
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. If set todefault(deprecated), attempt to connect to the first IP address returned by the lookup, even if the lookup returns multiple IP addresses.Type: string Default: use_all_dns_ips Valid Values: [default, 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: 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 0 (i.e. no delay). Settinglinger.ms=5, for example, would have the effect of reducing the number of requests sent but would add up to 5ms of latency to records sent in the absence of load.Type: long Default: 0 Valid Values: [0,...] Importance: medium max.block.ms
The configuration controls how long
KafkaProducer.send()andKafkaProducer.partitionsFor()will block.These methods can be blocked either because the buffer is full or metadata unavailable.Blocking in the user-supplied serializers or partitioner will not be counted against this 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
Partitioner class that implements the
org.apache.kafka.clients.producer.Partitionerinterface.Type: class Default: org.apache.kafka.clients.producer.internals.DefaultPartitioner 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 security.protocol
Protocol used to communicate with brokers. Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL.
Type: string Default: PLAINTEXT Valid Values: 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' when running with Java 11 or newer, 'TLSv1.2' otherwise. With the default value for Java 11, 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 cases. Also see the config documentation for `ssl.protocol`.
Type: list Default: TLSv1.2 Valid Values: Importance: medium ssl.keystore.type
The file format of the key store file. This is optional for client.
Type: string Default: JKS Valid Values: Importance: medium ssl.protocol
The SSL protocol used to generate the SSLContext. The default is 'TLSv1.3' when running with Java 11 or newer, 'TLSv1.2' otherwise. This value should be fine for most use cases. Allowed values in recent JVMs are 'TLSv1.2' and 'TLSv1.3'. 'TLS', 'TLSv1.1', 'SSL', 'SSLv2' and 'SSLv3' may be supported in older JVMs, but their usage is discouraged due to known security vulnerabilities. With the default value for this config and 'ssl.enabled.protocols', clients will downgrade to 'TLSv1.2' if the server does not support 'TLSv1.3'. If this config is set to 'TLSv1.2', 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: TLSv1.2 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.
Type: string Default: JKS Valid Values: Importance: medium 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,retriesto be greater than 0 andacksmust be 'all'. If these values are not explicitly set by the user, suitable values will be chosen. If incompatible values are set, aConfigExceptionwill be thrown.Type: boolean Default: false 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 setting is set to be greater than 1 and there are failed sends, there is a risk of message re-ordering due to retries (i.e., if retries are enabled).
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 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. The JmxReporter is always included to register JMX statistics.Type: list Default: "" 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.
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 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.
Type: long Default: 50 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.
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.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 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
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 ms that the transaction coordinator will wait for a transaction status update from the producer before proactively aborting the ongoing transaction.If this value is larger than the transaction.max.timeout.ms setting in the broker, the request will fail with a
InvalidTransactionTimeouterror.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 to use for establishing the initial connection to the Kafka cluster. The client will make use of all servers irrespective of which servers are specified here for bootstrapping—this list only impacts the initial hosts used to discover the full set of servers. This list should be in the form
host1:port1,host2:port2,.... Since these servers are just used for the initial connection to discover the full cluster membership (which may change dynamically), this list need not contain the full set of servers (you may want more than one, though, in case a server is down).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 a single byte of data is available or the fetch request times out waiting for data to arrive. Setting this to something greater than 1 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 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.Type: int Default: 10000 (10 seconds) Valid Values: Importance: high ssl.key.password
The password of the private key in the key store file. This is optional for client.
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.
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 access to the truststore is still available, but integrity checking is disabled.
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 `false` 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
- none: throw exception to the consumer if no previous offset is found for the consumer's group
- anything else: throw exception to the consumer.
Type: string Default: latest Valid Values: [latest, earliest, none] 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. If set todefault(deprecated), attempt to connect to the first IP address returned by the lookup, even if the lookup returns multiple IP addresses.Type: string Default: use_all_dns_ips Valid Values: [default, 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: 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().
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.
In addition to the default class specified below, you can use the
org.apache.kafka.clients.consumer.RoundRobinAssignorclass for round robin assignments of partitions to consumers.Implementing the
org.apache.kafka.clients.consumer.ConsumerPartitionAssignorinterface allows you to plug in a custom assignmentstrategy.Type: list Default: class org.apache.kafka.clients.consumer.RangeAssignor 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 security.protocol
Protocol used to communicate with brokers. Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL.
Type: string Default: PLAINTEXT Valid Values: 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' when running with Java 11 or newer, 'TLSv1.2' otherwise. With the default value for Java 11, 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 cases. Also see the config documentation for `ssl.protocol`.
Type: list Default: TLSv1.2 Valid Values: Importance: medium ssl.keystore.type
The file format of the key store file. This is optional for client.
Type: string Default: JKS Valid Values: Importance: medium ssl.protocol
The SSL protocol used to generate the SSLContext. The default is 'TLSv1.3' when running with Java 11 or newer, 'TLSv1.2' otherwise. This value should be fine for most use cases. Allowed values in recent JVMs are 'TLSv1.2' and 'TLSv1.3'. 'TLS', 'TLSv1.1', 'SSL', 'SSLv2' and 'SSLv3' may be supported in older JVMs, but their usage is discouraged due to known security vulnerabilities. With the default value for this config and 'ssl.enabled.protocols', clients will downgrade to 'TLSv1.2' if the server does not support 'TLSv1.3'. If this config is set to 'TLSv1.2', 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: TLSv1.2 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.
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 fetch.max.wait.ms
The maximum amount of time the server will block before answering the fetch request if there isn't sufficient data to immediately satisfy the requirement given by fetch.min.bytes.
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 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. The JmxReporter is always included to register JMX statistics.Type: list Default: "" 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.
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 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.
Type: long Default: 50 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.
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.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 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
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 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 to use for establishing the initial connection to the Kafka cluster. The client will make use of all servers irrespective of which servers are specified here for bootstrapping—this list only impacts the initial hosts used to discover the full set of servers. This list should be in the form
host1:port1,host2:port2,.... Since these servers are just used for the initial connection to discover the full cluster membership (which may change dynamically), this list need not contain the full set of servers (you may want more than one, though, in case a server is down).Type: list Default: localhost:9092 Valid Values: 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. This is optional for client.
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.
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 access to the truststore is still available, but integrity checking is disabled.
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. If set todefault(deprecated), attempt to connect to the first IP address returned by the lookup, even if the lookup returns multiple IP addresses.Type: string Default: use_all_dns_ips Valid Values: [default, 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 overriden by the connector. The default implementation is `None`. The other possible policies in the framework include `All` and `Principal`.Type: string Default: None 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: [0,...] 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 security.protocol
Protocol used to communicate with brokers. Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL.
Type: string Default: PLAINTEXT Valid Values: 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: [0,...] Importance: medium ssl.enabled.protocols
The list of protocols enabled for SSL connections. The default is 'TLSv1.2,TLSv1.3' when running with Java 11 or newer, 'TLSv1.2' otherwise. With the default value for Java 11, 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 cases. Also see the config documentation for `ssl.protocol`.
Type: list Default: TLSv1.2 Valid Values: Importance: medium ssl.keystore.type
The file format of the key store file. This is optional for client.
Type: string Default: JKS Valid Values: Importance: medium ssl.protocol
The SSL protocol used to generate the SSLContext. The default is 'TLSv1.3' when running with Java 11 or newer, 'TLSv1.2' otherwise. This value should be fine for most use cases. Allowed values in recent JVMs are 'TLSv1.2' and 'TLSv1.3'. 'TLS', 'TLSv1.1', 'SSL', 'SSLv2' and 'SSLv3' may be supported in older JVMs, but their usage is discouraged due to known security vulnerabilities. With the default value for this config and 'ssl.enabled.protocols', clients will downgrade to 'TLSv1.2' if the server does not support 'TLSv1.3'. If this config is set to 'TLSv1.2', 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: TLSv1.2 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.
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: org.apache.kafka.connect.runtime.WorkerConfig$AdminListenersValidator@d2cc05a 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
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 requests
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
Type: list Default: HmacSHA256 Valid Values: A list of one or more MAC algorithms, each supported by the worker JVM Importance: low internal.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. This setting controls the format used for internal bookkeeping data used by the framework, such as configs and offsets, so users can typically use any functioning Converter implementation. Deprecated; will be removed in an upcoming version.
Type: class Default: org.apache.kafka.connect.json.JsonConverter Valid Values: Importance: low internal.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. This setting controls the format used for internal bookkeeping data used by the framework, such as configs and offsets, so users can typically use any functioning Converter implementation. Deprecated; will be removed in an upcoming version.
Type: class Default: org.apache.kafka.connect.json.JsonConverter Valid Values: 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: null 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 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. The JmxReporter is always included to register JMX statistics.Type: list Default: "" 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.
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.
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.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.
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 rest.host.name
Hostname for the REST API. If this is set, it will only bind to this interface.
Type: string Default: null Valid Values: Importance: low rest.port
Port for the REST API to listen on.
Type: int Default: 8083 Valid Values: 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.
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.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 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 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 requested , 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: 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
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 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: 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: 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: 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 the include in the log the Connect record that resulted in a failure. This is 'false' by default, which will prevent record keys, values, and headers from being written to log files, although some information such as topic and partition number will still be logged.
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
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 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: 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: 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: 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 the include in the log the Connect record that resulted in a failure. This is 'false' by default, which will prevent record keys, values, and headers from being written to log files, although some information such as topic and partition number will still be logged.
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 to use for establishing the initial connection to the Kafka cluster. The client will make use of all servers irrespective of which servers are specified here for bootstrapping—this list only impacts the initial hosts used to discover the full set of servers. This list should be in the form
host1:port1,host2:port2,.... Since these servers are just used for the initial connection to discover the full cluster membership (which may change dynamically), this list need not contain the full set of servers (you may want more than one, though, in case a server is down).Type: list Default: Valid Values: Importance: high replication.factor
The replication factor for change log topics and repartition topics created by the stream processing application.
Type: int Default: 1 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.
Type: string Default: /tmp/kafka-streams 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 for an active task.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 consumer, producer and restore-consumer, with pattern '
-StreamThread- - Type: string Default: "" 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. Note when windowed serde class is used, one needs to set the inner serde class that implements theorg.apache.kafka.common.serialization.Serdeinterface via 'default.windowed.key.serde.inner' or 'default.windowed.value.serde.inner' as wellType: class Default: org.apache.kafka.common.serialization.Serdes$ByteArraySerde 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. Note when windowed serde class is used, one needs to set the inner serde class that implements theorg.apache.kafka.common.serialization.Serdeinterface via 'default.windowed.key.serde.inner' or 'default.windowed.value.serde.inner' as wellType: class Default: org.apache.kafka.common.serialization.Serdes$ByteArraySerde Valid Values: Importance: medium default.windowed.key.serde.inner
Default serializer / deserializer for the inner class of a windowed key. Must implement the
org.apache.kafka.common.serialization.Serdeinterface.Type: class Default: null Valid Values: Importance: medium default.windowed.value.serde.inner
Default serializer / deserializer for the inner class of a windowed value. Must implement the
org.apache.kafka.common.serialization.Serdeinterface.Type: class Default: null Valid Values: Importance: medium max.task.idle.ms
Maximum amount of time a stream task will stay idle when not all of its partition buffers contain records, to avoid potential out-of-order record processing across multiple input streams.
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.
Type: int Default: 2 Valid Values: [1,...] Importance: medium num.standby.replicas
The number of standby replicas for each task.
Type: int Default: 0 Valid Values: Importance: medium num.stream.threads
The number of threads to execute stream processing.
Type: int Default: 1 Valid Values: Importance: medium processing.guarantee
The processing guarantee that should be used. Possible values are
at_least_once(default),exactly_once(requires brokers version 0.11.0 or higher), andexactly_once_beta(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, exactly_once_beta] Importance: medium security.protocol
Protocol used to communicate with brokers. Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL.
Type: string Default: PLAINTEXT Valid Values: Importance: medium topology.optimization
A configuration telling Kafka Streams if it should optimize the topology, disabled by default
Type: string Default: none Valid Values: [none, all] 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: [0.10.0-2.4, latest] Importance: low commit.interval.ms
The frequency with which to save the position of the processor. (Note, if
processing.guaranteeis set toexactly_once, 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 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 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. The JmxReporter is always included to register JMX statistics.Type: list Default: "" 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.
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 partition.grouper
Partition grouper class that implements the
org.apache.kafka.streams.processor.PartitionGrouperinterface. WARNING: This config is deprecated and will be removed in 3.0.0 release.Type: class Default: org.apache.kafka.streams.processor.DefaultPartitionGrouper Valid Values: 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 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 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.
Type: long Default: 50 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 retries
Setting a value greater than zero will cause the client to resend any request that fails with a potentially transient error.
Type: int Default: 0 Valid Values: [0,...,2147483647] 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.
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 upgrading in a backward compatible way. This is needed when upgrading from [0.10.0, 1.1] to 2.0+, or when upgrading from [2.0, 2.3] to 2.4+. When upgrading from 2.4 to a newer version it is not required to specify this config. Default is `null`. Accepted values are "0.10.0", "0.10.1", "0.10.2", "0.11.0", "1.0", "1.1", "2.0", "2.1", "2.2", "2.3" (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] 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.servers
A list of host/port pairs to use for establishing the initial connection to the Kafka cluster. The client will make use of all servers irrespective of which servers are specified here for bootstrapping—this list only impacts the initial hosts used to discover the full set of servers. This list should be in the form
host1:port1,host2:port2,.... Since these servers are just used for the initial connection to discover the full cluster membership (which may change dynamically), this list need not contain the full set of servers (you may want more than one, though, in case a server is down).Type: list Default: Valid Values: Importance: high ssl.key.password
The password of the private key in the key store file. This is optional for client.
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.
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 access to the truststore is still available, but integrity checking is disabled.
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. If set todefault(deprecated), attempt to connect to the first IP address returned by the lookup, even if the lookup returns multiple IP addresses.Type: string Default: use_all_dns_ips Valid Values: [default, 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 security.protocol
Protocol used to communicate with brokers. Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL.
Type: string Default: PLAINTEXT Valid Values: 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' when running with Java 11 or newer, 'TLSv1.2' otherwise. With the default value for Java 11, 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 cases. Also see the config documentation for `ssl.protocol`.
Type: list Default: TLSv1.2 Valid Values: Importance: medium ssl.keystore.type
The file format of the key store file. This is optional for client.
Type: string Default: JKS Valid Values: Importance: medium ssl.protocol
The SSL protocol used to generate the SSLContext. The default is 'TLSv1.3' when running with Java 11 or newer, 'TLSv1.2' otherwise. This value should be fine for most use cases. Allowed values in recent JVMs are 'TLSv1.2' and 'TLSv1.3'. 'TLS', 'TLSv1.1', 'SSL', 'SSLv2' and 'SSLv3' may be supported in older JVMs, but their usage is discouraged due to known security vulnerabilities. With the default value for this config and 'ssl.enabled.protocols', clients will downgrade to 'TLSv1.2' if the server does not support 'TLSv1.3'. If this config is set to 'TLSv1.2', 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: TLSv1.2 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.
Type: string Default: JKS Valid Values: Importance: medium 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 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. The JmxReporter is always included to register JMX statistics.Type: list Default: "" 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.
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 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.
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.
Type: int Default: 2147483647 Valid Values: [0,...,2147483647] Importance: low retry.backoff.ms
The amount of time to wait before attempting to retry a failed request. This avoids repeatedly sending requests in a tight loop under some failure scenarios.
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.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 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
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