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https://issues.apache.org/jira/browse/FLINK-18451?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17168738#comment-17168738
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Till Rohrmann commented on FLINK-18451:
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Does your middleware support to replay the data (e.g. read the data starting
from some offset)? This is a requirement of Flink otherwise you will also
experience data loss in cases where you don't have two consumers running but
simply encounter a failover. The restarted task needs to be able to resume
reading the data from the last completed checkpoint because everything which
happened in between (between the last successful checkpoint and the failure) is
not guaranteed to be output/materialized.
> Flink HA on yarn may appear TaskManager double running when HA is restored
> --------------------------------------------------------------------------
>
> Key: FLINK-18451
> URL: https://issues.apache.org/jira/browse/FLINK-18451
> Project: Flink
> Issue Type: Bug
> Components: Deployment / YARN
> Affects Versions: 1.9.0
> Reporter: ming li
> Priority: Major
> Labels: high-availability
>
> We found that when NodeManager is lost, the new JobManager will be restored
> by Yarn's ResourceManager, and the Leader node will be registered on
> Zookeeper. The original TaskManager will find the new JobManager through
> Zookeeper and close the old JobManager connection. At this time, all tasks of
> the TaskManager will fail. The new JobManager will directly perform job
> recovery and recover from the latest checkpoint.
> However, during the recovery process, when a TaskManager is abnormally
> connected to Zookeeper, it is not registered with the new JobManager in time.
> Before the following timeout:
> 1. Connect with Zookeeper
> 2. Heartbeat with JobManager/ResourceManager
> Task will continue to run (assuming that Task can run independently in
> TaskManager). Assuming that HA recovers fast enough, some Task double runs
> will occur at this time.
> Do we need to make a persistent record of the cluster resources we allocated
> during the runtime, and use it to judge all Task stops when HA is restored?
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