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https://issues.apache.org/jira/browse/FLINK-14074?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16932634#comment-16932634
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Till Rohrmann commented on FLINK-14074:
---------------------------------------
Thanks a lot for looking into the problem in more depth [~Atlaster]. In the
{{YarnResourceManager}} we always check whether a new container needs to be
started if a container/task stops or cannot get started via:
https://github.com/apache/flink/blob/master/flink-yarn/src/main/java/org/apache/flink/yarn/YarnResourceManager.java#L510.
Since we restart failed Mesos tasks in
https://github.com/apache/flink/blob/master/flink-mesos/src/main/java/org/apache/flink/mesos/runtime/clusterframework/MesosResourceManager.java#L668
the only way I can think of how we could "lose" Mesos tasks is at start up
which is not reported or maybe there is a problem with the matching of pending
slots
https://github.com/apache/flink/blob/master/flink-runtime/src/main/java/org/apache/flink/runtime/resourcemanager/slotmanager/SlotManagerImpl.java#L594.
For the latter problem it would be interesting to see with which slot profile
the {{TaskManagers}} are being started and which profile the slots report when
they register.
> MesosResourceManager can't create new taskmanagers in Session Cluster Mode.
> ---------------------------------------------------------------------------
>
> Key: FLINK-14074
> URL: https://issues.apache.org/jira/browse/FLINK-14074
> Project: Flink
> Issue Type: Bug
> Components: Deployment / Mesos
> Affects Versions: 1.9.0
> Environment: Flink HA Session cluster 1.9.0 on mesos.
> Reporter: Alexander Kasyanenko
> Priority: Major
>
> Hi, I'm trying to launch multiple jobs in Flink Session Cluster, deployed on
> mesos.
> Flink's version is 1.9.0.
> The very first resource allocation completes successfully, and first
> submitted job launches, but submitting any amount of jobs afterwords doesn't
> affect the cluster in any way and no additional TaskManagers are allocated.
> From the logs I see that MesosResourceManager is requesting Slots for the
> newly submitted jobs: "{{o.a.f.m.r.c.MesosResourceManager - Request slot
> with profile ResourceProfile..."}} but line {{"Starting a new worker.}}"
> appears in log only the same amount of times as taskmanagers count, allocated
> for the first job.
> I'm a complete noob in flink internals, but took a wild guess about a reason.
> I think that the problem is in this check:
> [https://github.com/apache/flink/blob/release-1.9.0/flink-mesos/src/main/java/org/apache/flink/mesos/runtime/clusterframework/MesosResourceManager.java#L436]
> It might be that RM is lazily allocated at the first call by a factory, and
> then a private final field {{slotsPerWorker}} is set. So this check will
> prevent creation of any new worker after iterator traverses the entire
> collection. My main assumption is that {{slotsPerWorker}} is never modified
> again.
>
> I'm sorry that I didn't do much of investigation before reporting, but I'll
> try to do some after a weekend. I plan to build flink without this check and
> see if it helps. Also I'll play around with tests for this RM. Since it's my
> time running time flink internals, I'll be back after a few days.
> Any help will much appreciated.
> Thanks in advance.
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