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https://issues.apache.org/jira/browse/FLINK-17075?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17083964#comment-17083964
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Till Rohrmann commented on FLINK-17075:
---------------------------------------

I agree that retries will decrease the likelihood of missed messages. However, 
I don't fully understand why this will guarantee that the JM and TM won't go 
out of sync. Can't it still happen that all retries (assuming finite number of 
retries) for a final state update will fail and, hence, the JM will never learn 
about the terminal state? Also failing the {{Task}} on the {{TaskExecutor}} 
won't guarantee that the {{FAILING}} state transition will be sent to the JM 
(it will simply increase the number of retries of 
{{updateTaskExecutionState}}). 

Note that if the heartbeats fail, then the JM will disconnect from the TM which 
has the effect to fail all {{Executions}}. I think the situation we are 
discussing here is that there is a short-lived network problem which can be 
recovered by Akka and does not trigger the heartbeat to fail.

> Add task status reconciliation between TM and JM
> ------------------------------------------------
>
>                 Key: FLINK-17075
>                 URL: https://issues.apache.org/jira/browse/FLINK-17075
>             Project: Flink
>          Issue Type: Improvement
>          Components: Runtime / Coordination
>    Affects Versions: 1.10.0, 1.11.0
>            Reporter: Till Rohrmann
>            Priority: Critical
>             Fix For: 1.11.0
>
>
> In order to harden the TM and JM communication I suggest to let the 
> {{TaskExecutor}} send the task statuses back to the {{JobMaster}} as part of 
> the heartbeat payload (similar to FLINK-11059). This would allow to reconcile 
> the states of both components in case that a status update message was lost 
> as described by a user on the ML.
> https://lists.apache.org/thread.html/ra9ed70866381f0ef0f4779633346722ccab3dc0d6dbacce04080b74e%40%3Cuser.flink.apache.org%3E



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