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https://issues.apache.org/jira/browse/FLINK-9567?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16516972#comment-16516972
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Shimin Yang commented on FLINK-9567:
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Thanks for assigning the issue to me, I will do my best to fix it.
> Flink does not release resource in Yarn Cluster mode
> ----------------------------------------------------
>
> Key: FLINK-9567
> URL: https://issues.apache.org/jira/browse/FLINK-9567
> Project: Flink
> Issue Type: Bug
> Components: Cluster Management, YARN
> Affects Versions: 1.5.0
> Reporter: Shimin Yang
> Assignee: Shimin Yang
> Priority: Critical
> Fix For: 1.6.0
>
> Attachments: FlinkYarnProblem, fulllog.txt
>
>
> After restart the Job Manager in Yarn Cluster mode, sometimes Flink does not
> release task manager containers in some specific case. In the worst case, I
> had a job configured to 5 task managers, but possess more than 100 containers
> in the end. Although the task didn't failed, but it affect other jobs in the
> Yarn Cluster.
> In the first log I posted, the container with id 24 is the reason why Yarn
> did not release resources. As the container was killed before restart, but it
> has not received the callback of *onContainerComplete* in
> *YarnResourceManager* which should be called by *AMRMAsyncClient* of Yarn.
> After restart, as we can see in line 347 of FlinkYarnProblem log,
> 2018-06-14 22:50:47,846 WARN akka.remote.ReliableDeliverySupervisor -
> Association with remote system [akka.tcp://flink@bd-r1hdp69:30609] has
> failed, address is now gated for [50] ms. Reason: [Disassociated]
> Flink lost the connection of container 24 which is on bd-r1hdp69 machine.
> When it try to call *closeTaskManagerConnection* in *onContainerComplete*, it
> did not has the connection to TaskManager on container 24, so it just ignore
> the close of TaskManger.
> 2018-06-14 22:50:51,812 DEBUG org.apache.flink.yarn.YarnResourceManager - No
> open TaskExecutor connection container_1528707394163_29461_02_000024.
> Ignoring close TaskExecutor connection.
> However, bafore calling *closeTaskManagerConnection,* it already called
> *requestYarnContainer* which lead to *numPendingContainerRequests variable
> in* *YarnResourceManager* increased by 1.
> As the excessive container return is determined by the
> *numPendingContainerRequests* variable in *YarnResourceManager*, it cannot
> return this container although it is not required. Meanwhile, the restart
> logic has already allocated enough containers for Task Managers, Flink will
> possess the extra container for a long time for nothing.
> In the full log, the job ended with 7 containers while only 3 are running
> TaskManagers.
> ps: Another strange thing I found is that when sometimes request for a yarn
> container, it will return much more than requested. Is it a normal scenario
> for AMRMAsyncClient?
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