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https://issues.apache.org/jira/browse/KAFKA-4479?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16567529#comment-16567529
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Matthias J. Sax commented on KAFKA-4479:
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Just re-reading the description: Streams does not send a "leave group request"
in close() – this is an internal setting to allow for rolling bounce upgrades
without state migration. Seems to be related. However, I haven't seen any
failure of `QueryableStateIntegrationTest` for quite some time. Maybe we can
close this a cannot reproduce?
> Streams tests should pass without hardcoded Time.SYSTEM in GroupCoordinator
> ---------------------------------------------------------------------------
>
> Key: KAFKA-4479
> URL: https://issues.apache.org/jira/browse/KAFKA-4479
> Project: Kafka
> Issue Type: Improvement
> Components: streams, unit tests
> Reporter: Ismael Juma
> Priority: Minor
> Labels: newbie, newbie++
> Attachments: test.zip
>
>
> If we pass `KafkaServer.time` to `GroupCoordinator`[1], some streams tests
> like QueryableStateIntegrationTest fail sem-regularly. [~damianguy] looked
> into it and described it as:
> {quote}
> Looking at the sequence of events, one thread is stopped, and hence leaves
> the group triggering a rebalance, but the other thread doesn’t seem to get
> the memo, tries to commit, fails, and then game-over.
> So.. the case that it fails the one alive thread is not getting a rebalance.
> This would happen during a `poll(..)` right? However i can see the thread is
> polling many times after the other thread has shutdown.
> It tries to commit every time around the loop, so:
> poll(..)
> process(..)
> maybeCommit(..)
> and there is like < 10ms between calls to `poll`.
> {quote}
> A theory was that the mock time was not advancing enough to trigger a
> rebalance in the group coordinator. However, the consumer is closed, so that
> should trigger a `LeaveGroup` request and it's unclear why a rebalance is not
> triggered for the live consumer.
> PR where this issue was first seen and discussed:
> https://github.com/apache/kafka/pull/2095
> [1]
> https://github.com/apache/kafka/blob/trunk/core/src/main/scala/kafka/server/KafkaServer.scala#L222
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