Monitoring

Monitoring

Kafka uses Yammer Metrics for metrics reporting in both the server and the client. This can be configured to report stats using pluggable stats reporters to hook up to your monitoring system.

The easiest way to see the available metrics to fire up jconsole and point it at a running kafka client or server; this will all browsing all metrics with JMX.

of under replicated partitions (|ISR| < |all replicas|) | kafka.server:type=ReplicaManager,name=UnderReplicatedPartitions | 0

Is controller active on broker | kafka.controller:type=KafkaController,name=ActiveControllerCount | only one broker in the cluster should have 1
Leader election rate | kafka.controller:type=ControllerStats,name=LeaderElectionRateAndTimeMs | non-zero when there are broker failures
Unclean leader election rate | kafka.controller:type=ControllerStats,name=UncleanLeaderElectionsPerSec | 0
Partition counts | kafka.server:type=ReplicaManager,name=PartitionCount | mostly even across brokers
Leader replica counts | kafka.server:type=ReplicaManager,name=LeaderCount | mostly even across brokers
ISR shrink rate | kafka.server:type=ReplicaManager,name=IsrShrinksPerSec | If a broker goes down, ISR for some of the partitions will shrink. When that broker is up again, ISR will be expanded once the replicas are fully caught up. Other than that, the expected value for both ISR shrink rate and expansion rate is 0.
ISR expansion rate | kafka.server:type=ReplicaManager,name=IsrExpandsPerSec | See above
Max lag in messages btw follower and leader replicas | kafka.server:type=ReplicaFetcherManager,name=MaxLag,clientId=Replica | lag should be proportional to the maximum batch size of a produce request.
Lag in messages per follower replica | kafka.server:type=FetcherLagMetrics,name=ConsumerLag,clientId=([-.\\w]+),topic=([-.\\w]+),partition=([0-9]+) | lag should be proportional to the maximum batch size of a produce request.
Requests waiting in the producer purgatory | kafka.server:type=ProducerRequestPurgatory,name=PurgatorySize | non-zero if ack=-1 is used
Requests waiting in the fetch purgatory | kafka.server:type=FetchRequestPurgatory,name=PurgatorySize | size depends on fetch.wait.max.ms in the consumer
Request total time | kafka.network:type=RequestMetrics,name=TotalTimeMs,request={Produce|FetchConsumer|FetchFollower} | broken into queue, local, remote and response send time
Time the request waiting in the request queue | kafka.network:type=RequestMetrics,name=QueueTimeMs,request={Produce|FetchConsumer|FetchFollower} |
Time the request being processed at the leader | kafka.network:type=RequestMetrics,name=LocalTimeMs,request={Produce|FetchConsumer|FetchFollower} |
Time the request waits for the follower | kafka.network:type=RequestMetrics,name=RemoteTimeMs,request={Produce|FetchConsumer|FetchFollower} | non-zero for produce requests when ack=-1
Time to send the response | kafka.network:type=RequestMetrics,name=ResponseSendTimeMs,request={Produce|FetchConsumer|FetchFollower} |
Number of messages the consumer lags behind the producer by | kafka.consumer:type=ConsumerFetcherManager,name=MaxLag,clientId=([-.\\w]+) |
The average fraction of time the network processors are idle | kafka.network:type=SocketServer,name=NetworkProcessorAvgIdlePercent | between 0 and 1, ideally > 0.3
The average fraction of time the request handler threads are idle | kafka.server:type=KafkaRequestHandlerPool,name=RequestHandlerAvgIdlePercent | between 0 and 1, ideally > 0.3
Quota metrics per client-id | kafka.server:type={Produce|Fetch},client-id==([-.\\w]+) | Two attributes. throttle-time indicates the amount of time in ms the client-id was throttled. Ideally = 0. byte-rate indicates the data produce/consume rate of the client in bytes/sec.

New producer monitoring

Audit

The final alerting we do is on the correctness of the data delivery. We audit that every message that is sent is consumed by all consumers and measure the lag for this to occur. For important topics we alert if a certain completeness is not achieved in a certain time period. The details of this are discussed in KAFKA-260.