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Posted to yarn-issues@hadoop.apache.org by "Eric Payne (JIRA)" <ji...@apache.org> on 2015/08/31 21:20:46 UTC

[jira] [Updated] (YARN-3769) Preemption occurring unnecessarily because preemption doesn't consider user limit

     [ https://issues.apache.org/jira/browse/YARN-3769?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Eric Payne updated YARN-3769:
-----------------------------
    Attachment: YARN-3769.001.branch-2.8.patch
                YARN-3769.001.branch-2.7.patch

{quote}
One thing I've thought for a while is adding a "lazy preemption" mechanism, which is: when a container is marked preempted and wait for max_wait_before_time, it becomes a "can_be_killed" container. If there's another queue can allocate on a node with "can_be_killed" container, such container will be killed immediately to make room the new containers.

I will upload a design doc shortly for review.
{quote}

[~leftnoteasy], because it's been a couple of months since the last activity on this JIRA, would it be better to use this JIRA for the purpose of making the preemption monitor "user-limit" aware and open a separate JIRA to address a redesign?

Towards that end, I am uploading a couple of patches:
- {{YARN-3769.001.branch-2.7.patch}} is a patch to 2.7 (and also 2.6) which we have been using internally. This fix has dramatically reduced the instances of "ping-pong"-ing as I outlined in [the comment above|https://issues.apache.org/jira/browse/YARN-3769?focusedCommentId=14573619&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14573619]. 
- {{YARN-3769.001.branch-2.8.patch}} is similar to the fix made in 2.7, but it also takes into consideration node label partitions.
Thanks for your help and please let me know what you think.

> Preemption occurring unnecessarily because preemption doesn't consider user limit
> ---------------------------------------------------------------------------------
>
>                 Key: YARN-3769
>                 URL: https://issues.apache.org/jira/browse/YARN-3769
>             Project: Hadoop YARN
>          Issue Type: Bug
>          Components: capacityscheduler
>    Affects Versions: 2.6.0, 2.7.0, 2.8.0
>            Reporter: Eric Payne
>            Assignee: Wangda Tan
>         Attachments: YARN-3769.001.branch-2.7.patch, YARN-3769.001.branch-2.8.patch
>
>
> We are seeing the preemption monitor preempting containers from queue A and then seeing the capacity scheduler giving them immediately back to queue A. This happens quite often and causes a lot of churn.



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