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https://issues.apache.org/jira/browse/FLINK-21248?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17278816#comment-17278816
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Till Rohrmann commented on FLINK-21248:
---------------------------------------
I am not sure whether FLINK-16177 really causes the problem you are
experiencing. The thing is that in your job the list of
{{OperatorCoordinators}} should be empty. Hence, the resulting future should be
completed immediately. Maybe you can check this.
For the offset committing, this is done not for failover but for diagnostic
reasons if I am not mistaken. Flink itself needs a Flink checkpoint to resume
from the point where it left off. Otherwise Flink will fallback to whatever you
have configured via {{auto.offset.reset}} if I am not mistaken.
> Checkpoint problem in 1.12.0
> ----------------------------
>
> Key: FLINK-21248
> URL: https://issues.apache.org/jira/browse/FLINK-21248
> Project: Flink
> Issue Type: Bug
> Components: Runtime / Checkpointing
> Affects Versions: 1.12.0
> Reporter: Ceyhan Kasap
> Priority: Major
>
> Hi
> I am trying to upgrade from 1.5.5 to 1.12 and checkpointing mechanism seems
> to be broken in our kafka connector sourced datastream jobs.
> Since there is a siginificant version gap and there are many backwards
> uncompatible / deprecated changes in flink runtime between versions, I had to
> modify our jobs and noticed that checkpoint offsets are not committed to
> kafka for source connectors.
> To simplfiy the issues I created simple repoducer projects:
> [https://github.com/simpleusr/flink_problem_1.5.5]
> [https://github.com/simpleusr/flink_problem_1.12.0]
> It seems that there are majr changes in the checkpoint infrastructure.
> For 1.5.5 checkpoint cycles works as expected as can be seen from the logs
> (please note that sample project contains a small hack in
> org.apache.flink.runtime.minicluster.MiniCluster which prevents cluster from
> stopping) :
> *[2021-02-03 10:04:17,409] INFO Completed checkpoint 2 for job
> 08eb15132225903b77ee44f5ca6ad2a5 (43764 bytes in 11 ms).
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:873)*
> *[2021-02-03 10:04:17,409] INFO Completed checkpoint 2 for job
> 08eb15132225903b77ee44f5ca6ad2a5 (43764 bytes in 11 ms).
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:873)*
> ....................
> *[2021-02-03 10:04:27,401] INFO Completed checkpoint 4 for job
> 08eb15132225903b77ee44f5ca6ad2a5 (43764 bytes in 5 ms).
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:873)*
> *[2021-02-03 10:04:27,401] INFO Completed checkpoint 4 for job
> 08eb15132225903b77ee44f5ca6ad2a5 (43764 bytes in 5 ms).
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:873)*
> However for 1.12.0 checkpoint cycles stuck at initial checkpoint:
> *[2021-02-03 10:06:24,504] INFO Triggering checkpoint 1 (type=CHECKPOINT) @
> 1612339584496 for job ce255b141393a358db734db2d27ef0ea.
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:710)*
> As far as I see, checkpoint cycle is stuck at waiting in
> org.apache.flink.runtime.checkpoint.CheckpointCoordinator for
> coordinatorCheckpointsComplete although coordinatorsToCheckpoint is empty...
>
> {code}
> final CompletableFuture<?> coordinatorCheckpointsComplete =
> pendingCheckpointCompletableFuture.thenComposeAsync(
> (pendingCheckpoint) ->
> OperatorCoordinatorCheckpoints
>
> .triggerAndAcknowledgeAllCoordinatorCheckpointsWithCompletion(
> coordinatorsToCheckpoint,
> pendingCheckpoint,
> timer),
> timer);
> {code}
> Simply returning from
> OperatorCoordinatorCheckpoints.triggerAndAcknowledgeAllCoordinatorCheckpointsWithCompletion
> when there is no coordinatorsToCheckpoint seems to resolve the problem:
> *[2021-02-03 10:07:53,387] INFO Triggering checkpoint 1 (type=CHECKPOINT) @
> 1612339673380 for job ffb4a06302f7e60e9325f32340d299b2.
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:710)*
> *[2021-02-03 10:07:53,387] INFO Triggering checkpoint 1 (type=CHECKPOINT) @
> 1612339673380 for job ffb4a06302f7e60e9325f32340d299b2.
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:710)*
> *[2021-02-03 10:07:53,607] INFO Completed checkpoint 1 for job
> ffb4a06302f7e60e9325f32340d299b2 (8324 bytes in 225 ms).
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:1131)*
> *[2021-02-03 10:07:53,607] INFO Completed checkpoint 1 for job
> ffb4a06302f7e60e9325f32340d299b2 (8324 bytes in 225 ms).
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:1131)*
> *[2021-02-03 10:07:58,380] INFO Triggering checkpoint 2 (type=CHECKPOINT) @
> 1612339678380 for job ffb4a06302f7e60e9325f32340d299b2.
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:710)*
> *[2021-02-03 10:07:58,380] INFO Triggering checkpoint 2 (type=CHECKPOINT) @
> 1612339678380 for job ffb4a06302f7e60e9325f32340d299b2.
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:710)*
> *[2021-02-03 10:07:58,388] INFO Completed checkpoint 2 for job
> ffb4a06302f7e60e9325f32340d299b2 (8324 bytes in 7 ms).
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:1131)*
> *[2021-02-03 10:07:58,388] INFO Completed checkpoint 2 for job
> ffb4a06302f7e60e9325f32340d299b2 (8324 bytes in 7 ms).
> (org.apache.flink.runtime.checkpoint.CheckpointCoordinator:1131)*
> I have submitted this pr for this.
> Please help me if I am missing something or there is another solution without
> code change.
> We need to perform the upgrade and modify our jobs as soon as possible (I
> hope other breaking changes do not happen) so any help will be appreciated..
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