[jira] [Commented] (KAFKA-2082) Kafka Replication ends up in a bad state

["Raghavendra Nandagopal (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/KAFKA-2082?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15286045#comment-15286045 ] 

Raghavendra Nandagopal commented on KAFKA-2082:
-----------------------------------------------

Hi,
  We are also seeing this issue in our production environment.  Is there any workaround?

Thanks

> Kafka Replication ends up in a bad state
> ----------------------------------------
>
>                 Key: KAFKA-2082
>                 URL: https://issues.apache.org/jira/browse/KAFKA-2082
>             Project: Kafka
>          Issue Type: Bug
>          Components: replication
>    Affects Versions: 0.8.2.1
>            Reporter: Evan Huus
>            Assignee: Sriharsha Chintalapani
>            Priority: Critical
>              Labels: zkclient-problems
>         Attachments: KAFKA-2082.patch
>
>
> While running integration tests for Sarama (the go client) we came across a pattern of connection losses that reliably puts kafka into a bad state: several of the brokers start spinning, chewing ~30% CPU and spamming the logs with hundreds of thousands of lines like:
> {noformat}
> [2015-04-01 13:08:40,070] WARN [Replica Manager on Broker 9093]: Fetch request with correlation id 111094 from client ReplicaFetcherThread-0-9093 on partition [many_partition,1] failed due to Leader not local for partition [many_partition,1] on broker 9093 (kafka.server.ReplicaManager)
> [2015-04-01 13:08:40,070] WARN [Replica Manager on Broker 9093]: Fetch request with correlation id 111094 from client ReplicaFetcherThread-0-9093 on partition [many_partition,6] failed due to Leader not local for partition [many_partition,6] on broker 9093 (kafka.server.ReplicaManager)
> [2015-04-01 13:08:40,070] WARN [Replica Manager on Broker 9093]: Fetch request with correlation id 111095 from client ReplicaFetcherThread-0-9093 on partition [many_partition,21] failed due to Leader not local for partition [many_partition,21] on broker 9093 (kafka.server.ReplicaManager)
> [2015-04-01 13:08:40,071] WARN [Replica Manager on Broker 9093]: Fetch request with correlation id 111095 from client ReplicaFetcherThread-0-9093 on partition [many_partition,26] failed due to Leader not local for partition [many_partition,26] on broker 9093 (kafka.server.ReplicaManager)
> [2015-04-01 13:08:40,071] WARN [Replica Manager on Broker 9093]: Fetch request with correlation id 111095 from client ReplicaFetcherThread-0-9093 on partition [many_partition,1] failed due to Leader not local for partition [many_partition,1] on broker 9093 (kafka.server.ReplicaManager)
> [2015-04-01 13:08:40,071] WARN [Replica Manager on Broker 9093]: Fetch request with correlation id 111095 from client ReplicaFetcherThread-0-9093 on partition [many_partition,6] failed due to Leader not local for partition [many_partition,6] on broker 9093 (kafka.server.ReplicaManager)
> [2015-04-01 13:08:40,072] WARN [Replica Manager on Broker 9093]: Fetch request with correlation id 111096 from client ReplicaFetcherThread-0-9093 on partition [many_partition,21] failed due to Leader not local for partition [many_partition,21] on broker 9093 (kafka.server.ReplicaManager)
> [2015-04-01 13:08:40,072] WARN [Replica Manager on Broker 9093]: Fetch request with correlation id 111096 from client ReplicaFetcherThread-0-9093 on partition [many_partition,26] failed due to Leader not local for partition [many_partition,26] on broker 9093 (kafka.server.ReplicaManager)
> {noformat}
> This can be easily and reliably reproduced using the {{toxiproxy-final}} branch of https://github.com/Shopify/sarama which includes a vagrant script for provisioning the appropriate cluster: 
> - {{git clone https://github.com/Shopify/sarama.git}}
> - {{git checkout test-jira-kafka-2082}}
> - {{vagrant up}}
> - {{TEST_SEED=1427917826425719059 DEBUG=true go test -v}}
> After the test finishes (it fails because the cluster ends up in a bad state), you can log into the cluster machine with {{vagrant ssh}} and inspect the bad nodes. The vagrant script provisions five zookeepers and five brokers in {{/opt/kafka-9091/}} through {{/opt/kafka-9095/}}.
> Additional context: the test produces continually to the cluster while randomly cutting and restoring zookeeper connections (all connections to zookeeper are run through a simple proxy on the same vm to make this easy). The majority of the time this works very well and does a good job exercising our producer's retry and failover code. However, under certain patterns of connection loss (the {{TEST_SEED}} in the instructions is important), kafka gets confused. The test never cuts more than two connections at a time, so zookeeper should always have quorum, and the topic (with three replicas) should always be writable.
> Completely restarting the cluster via {{vagrant reload}} seems to put it back into a sane state.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)