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https://issues.apache.org/jira/browse/FLINK-7844?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16210134#comment-16210134
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Zhenzhong Xu commented on FLINK-7844:
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[~till.rohrmann] Another question regarding checkpoint timeouts.
I looked at the code, it seems that checkpoint times out configured amount of
time after the initial checkpoint got triggered. So in terms of a task manager
termination, if we set akka timeout to x seconds, that means job manager won't
perform fine-grained recovery until at least x seconds elapsed after tm
instance goes down. Now if checkpoint times out before akka timeout would that
cause confusion in some edge cases?
To summarize, what is the general recommendation in setting checkpoint timeouts
(a secs) in relation to akka timeouts (b secs). Is it right to assume a >= b
should be enforced?
> Fine Grained Recovery triggers checkpoint timeout failure
> ---------------------------------------------------------
>
> Key: FLINK-7844
> URL: https://issues.apache.org/jira/browse/FLINK-7844
> Project: Flink
> Issue Type: Bug
> Components: State Backends, Checkpointing
> Affects Versions: 1.4.0, 1.3.2
> Reporter: Zhenzhong Xu
> Assignee: Zhenzhong Xu
> Attachments: screenshot-1.png
>
>
> Context:
> We are using "individual" failover (fine-grained) recovery strategy for our
> embarrassingly parallel router use case. The topic has over 2000 partitions,
> and parallelism is set to ~180 that dispatched to over 20 task managers with
> around 180 slots.
> Observations:
> We've noticed after one task manager termination, even though the individual
> recovery happens correctly, that the workload was re-dispatched to a new
> available task manager instance. However, the checkpoint would take 10 mins
> to eventually timeout, causing all other task managers not able to commit
> checkpoints. In a worst-case scenario, if job got restarted for other reasons
> (i.e. job manager termination), that would cause more messages to be
> re-processed/duplicates compared to the job without fine-grained recovery
> enabled.
> I am suspecting that uber checkpoint was waiting for a previous checkpoint
> that initiated by the old task manager and thus taking a long time to time
> out.
> Two questions:
> 1. Is there a configuration that controls this checkpoint timeout?
> 2. Is there any reason that when Job Manager realizes that Task Manager is
> gone and workload is redispatched, it still need to wait for the checkpoint
> initiated by the old task manager?
> Checkpoint screenshot in attachments.
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