[
https://issues.apache.org/jira/browse/KAFKA-2674?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14997148#comment-14997148
]
ASF GitHub Bot commented on KAFKA-2674:
---------------------------------------
GitHub user hachikuji opened a pull request:
https://github.com/apache/kafka/pull/467
KAFKA-2674: clarify onPartitionsRevoked behavior
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/hachikuji/kafka KAFKA-2674
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/kafka/pull/467.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #467
----
commit 7922adfe74278f7f003d4053c7b6e06f618ab1a6
Author: Jason Gustafson <[email protected]>
Date: 2015-11-09T19:02:44Z
KAFKA-2674: clarify onPartitionsRevoked behavior
----
> ConsumerRebalanceListener.onPartitionsRevoked() is not called on consumer
> close
> -------------------------------------------------------------------------------
>
> Key: KAFKA-2674
> URL: https://issues.apache.org/jira/browse/KAFKA-2674
> Project: Kafka
> Issue Type: Bug
> Components: consumer
> Affects Versions: 0.9.0.0
> Reporter: Michal Turek
> Assignee: Jason Gustafson
>
> Hi, I'm investigating and testing behavior of new consumer from the planned
> release 0.9 and found an inconsistency in calling of rebalance callbacks.
> I noticed that ConsumerRebalanceListener.onPartitionsRevoked() is NOT called
> during consumer close and application shutdown. It's JavaDoc contract says:
> - "This method will be called before a rebalance operation starts and after
> the consumer stops fetching data."
> - "It is recommended that offsets should be committed in this callback to
> either Kafka or a custom offset store to prevent duplicate data."
> I believe calling consumer.close() is a start of rebalance operation and even
> the local consumer that is actually closing should be notified to be able to
> process any rebalance logic including offsets commit (e.g. if auto-commit is
> disabled).
> There are commented logs of current and expected behaviors.
> {noformat}
> // Application start
> 2015-10-20 15:14:02.208 INFO o.a.k.common.utils.AppInfoParser
> [TestConsumer-worker-0]: Kafka version : 0.9.0.0-SNAPSHOT
> (AppInfoParser.java:82)
> 2015-10-20 15:14:02.208 INFO o.a.k.common.utils.AppInfoParser
> [TestConsumer-worker-0]: Kafka commitId : 241b9ab58dcbde0c
> (AppInfoParser.java:83)
> // Consumer started (the first one in group), rebalance callbacks are called
> including empty onPartitionsRevoked()
> 2015-10-20 15:14:02.333 INFO c.a.e.kafka.newapi.TestConsumer
> [TestConsumer-worker-0]: Rebalance callback, revoked: []
> (TestConsumer.java:95)
> 2015-10-20 15:14:02.343 INFO c.a.e.kafka.newapi.TestConsumer
> [TestConsumer-worker-0]: Rebalance callback, assigned: [testB-1, testA-0,
> testB-0, testB-3, testA-2, testB-2, testA-1, testA-4, testB-4, testA-3]
> (TestConsumer.java:100)
> // Another consumer joined the group, rebalancing
> 2015-10-20 15:14:17.345 INFO o.a.k.c.c.internals.Coordinator
> [TestConsumer-worker-0]: Attempt to heart beat failed since the group is
> rebalancing, try to re-join group. (Coordinator.java:714)
> 2015-10-20 15:14:17.346 INFO c.a.e.kafka.newapi.TestConsumer
> [TestConsumer-worker-0]: Rebalance callback, revoked: [testB-1, testA-0,
> testB-0, testB-3, testA-2, testB-2, testA-1, testA-4, testB-4, testA-3]
> (TestConsumer.java:95)
> 2015-10-20 15:14:17.349 INFO c.a.e.kafka.newapi.TestConsumer
> [TestConsumer-worker-0]: Rebalance callback, assigned: [testB-3, testA-4,
> testB-4, testA-3] (TestConsumer.java:100)
> // Consumer started closing, there SHOULD be onPartitionsRevoked() callback
> to commit offsets like during standard rebalance, but it is missing
> 2015-10-20 15:14:39.280 INFO c.a.e.kafka.newapi.TestConsumer [main]:
> Closing instance (TestConsumer.java:42)
> 2015-10-20 15:14:40.264 INFO c.a.e.kafka.newapi.TestConsumer
> [TestConsumer-worker-0]: Worker thread stopped (TestConsumer.java:89)
> {noformat}
> Workaround is to call onPartitionsRevoked() explicitly and manually just
> before calling consumer.close() but it seems dirty and error prone for me. It
> can be simply forgotten be someone without such experience.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
