[jira] [Commented] (YARN-4606) CapacityScheduler: applications could get starved because computation of #activeUsers considers pending apps

["Manikandan R (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/YARN-4606?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16459882#comment-16459882 ] 

Manikandan R commented on YARN-4606:
------------------------------------

Attaching .001 patch containing test case for CS and changes required to fix the problem (activeUsersOfPendingApps being-ve issue) mentioned in my previous comment. Also, tested the patch in my pseudo setup for CS. I am planning to run all junits after the review.

{quote}AppSchedulingInfo is supports to cache status for pending resource, it might be better to avoid invoking SchedulerAppAttempt's method from AppSchedulingInfo.{quote}

[~leftnoteasy] As of now, {{AppSchedulingInfo}} calls only {{SchedulerAppAttempt#isWaitingForAMContainer}} to take some decision, for which I don't see any cache. Can you please explain?

> CapacityScheduler: applications could get starved because computation of #activeUsers considers pending apps 
> -------------------------------------------------------------------------------------------------------------
>
>                 Key: YARN-4606
>                 URL: https://issues.apache.org/jira/browse/YARN-4606
>             Project: Hadoop YARN
>          Issue Type: Bug
>          Components: capacity scheduler, capacityscheduler
>    Affects Versions: 2.8.0, 2.7.1
>            Reporter: Karam Singh
>            Assignee: Manikandan R
>            Priority: Critical
>         Attachments: YARN-4606.001.patch, YARN-4606.1.poc.patch, YARN-4606.POC.2.patch, YARN-4606.POC.patch
>
>
> Currently, if all applications belong to same user in LeafQueue are pending (caused by max-am-percent, etc.), ActiveUsersManager still considers the user is an active user. This could lead to starvation of active applications, for example:
> - App1(belongs to user1)/app2(belongs to user2) are active, app3(belongs to user3)/app4(belongs to user4) are pending
> - ActiveUsersManager returns #active-users=4
> - However, there're only two users (user1/user2) are able to allocate new resources. So computed user-limit-resource could be lower than expected.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: yarn-issues-unsubscribe@hadoop.apache.org
For additional commands, e-mail: yarn-issues-help@hadoop.apache.org