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https://issues.apache.org/jira/browse/FLINK-9567?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16527046#comment-16527046
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ASF GitHub Bot commented on FLINK-9567:
---------------------------------------
Github user Clarkkkkk commented on a diff in the pull request:
https://github.com/apache/flink/pull/6192#discussion_r199036840
--- Diff:
flink-yarn/src/main/java/org/apache/flink/yarn/YarnResourceManager.java ---
@@ -334,8 +335,11 @@ public void onContainersCompleted(final
List<ContainerStatus> list) {
if (yarnWorkerNode != null) {
// Container completed
unexpectedly ~> start a new one
final Container container =
yarnWorkerNode.getContainer();
-
requestYarnContainer(container.getResource(),
yarnWorkerNode.getContainer().getPriority());
-
closeTaskManagerConnection(resourceId, new
Exception(containerStatus.getDiagnostics()));
+ // check WorkerRegistration
status to avoid requesting containers more than required
+ if
(checkWorkerRegistrationWithResourceId(resourceId)) {
--- End diff --
Yes, I might happen. The problem is not as easy as I thought. The actual
cause of this problem is the resource was released before a full restart but
the onContainerCompleted callback method happened after the full restart. As
the full restart will requesting all the containers needed as configured, if
the onContainerCompleted method was called after that, it will request for a
new container and possess it which is not needed.
> 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
> Labels: pull-request-available
> 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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