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https://issues.apache.org/jira/browse/YARN-3849?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14601848#comment-14601848
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Wangda Tan commented on YARN-3849:
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[~sunilg],
Trying to understand this issue, when the toObtainResource becomes <10,0>, and
assume container size are c1=<2,1>, c2=<5,3>, c3=<4,2>, c4=<2,1>. Preemption
policy will kill c1..c3, my understanding of this problem is preemption policy
can preempt one of the resource type (CPU/Memory) more than needed, but I'm not
sure why it preempts all containers except AM.
> Too much of preemption activity causing continuos killing of containers
> across queues
> -------------------------------------------------------------------------------------
>
> Key: YARN-3849
> URL: https://issues.apache.org/jira/browse/YARN-3849
> Project: Hadoop YARN
> Issue Type: Bug
> Components: resourcemanager
> Affects Versions: 2.7.0
> Reporter: Sunil G
> Assignee: Sunil G
> Priority: Critical
>
> Two queues are used. Each queue has given a capacity of 0.5. Dominant
> Resource policy is used.
> 1. An app is submitted in QueueA which is consuming full cluster capacity
> 2. After submitting an app in QueueB, there are some demand and invoking
> preemption in QueueA
> 3. Instead of killing the excess of 0.5 guaranteed capacity, we observed that
> all containers other than AM is getting killed in QueueA
> 4. Now the app in QueueB is trying to take over cluster with the current free
> space. But there are some updated demand from the app in QueueA which lost
> its containers earlier, and preemption is kicked in QueueB now.
> Scenario in step 3 and 4 continuously happening in loop. Thus none of the
> apps are completing.
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