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https://issues.apache.org/jira/browse/YARN-2069?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14054346#comment-14054346
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Wangda Tan commented on YARN-2069:
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Hi [~mayank_bansal],
Please let me know if I didn't understand correctly,
For the following code snippet,
{code}
1      Resource userLimitforQueue = qT.leafQueue.computeUserLimit(fc,
2          clusterResource, Resources.none());
3      if (Resources.lessThan(rc, clusterResource, userLimitforQueue,
4          qT.leafQueue.getUser(fc.getUser()).getConsumedResources())) {
5
6        // As we have used more resources the user limit,
7        // we need to claim back the resources equivalent to
8        // consumed resources by user - user limit
9        Resource resourcesToClaimBackFromUser = Resources.subtract(qT.leafQueue
10          .getUser(fc.getUser()).getConsumedResources(), userLimitforQueue);
{code}
Line 1-4 will check if we need preempt resource from an application, because 
preemption is a delayed behavior, the "preemptFrom" will not change return 
value of qT.leafQueue.getUser(fc.getUser()).getConsumedResources(). So for 5 
apps of B, all its apps will be preempt line 9-10 containers. Is it correct?

> CS queue level preemption should respect user-limits
> ----------------------------------------------------
>
>                 Key: YARN-2069
>                 URL: https://issues.apache.org/jira/browse/YARN-2069
>             Project: Hadoop YARN
>          Issue Type: Sub-task
>          Components: capacityscheduler
>            Reporter: Vinod Kumar Vavilapalli
>            Assignee: Mayank Bansal
>         Attachments: YARN-2069-trunk-1.patch, YARN-2069-trunk-2.patch, 
> YARN-2069-trunk-3.patch
>
>
> This is different from (even if related to, and likely share code with) 
> YARN-2113.
> YARN-2113 focuses on making sure that even if queue has its guaranteed 
> capacity, it's individual users are treated in-line with their limits 
> irrespective of when they join in.
> This JIRA is about respecting user-limits while preempting containers to 
> balance queue capacities.



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