hadoop-yarn-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Wei Yan (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (YARN-596) In fair scheduler, intra-application container priorities affect inter-application preemption decisions
Date Tue, 08 Apr 2014 01:19:15 GMT

    [ https://issues.apache.org/jira/browse/YARN-596?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13962488#comment-13962488
] 

Wei Yan commented on YARN-596:
------------------------------

{quote}For preemptContainerPreCheck, it would be good to take multiple resources into account
(using the DefaultResourceCalculator will only apply to memory). Resources.fitsIn(getResourceUsage(),
getFairShare) can be used to determine whether a Schedulable is safe from preemption.{quote}
[~sandyr], so here the ''safe'' means "usage.memory > fairshare.memory and usage.vcores
> fairshare.vcores"? But the fairshare.vcores for FSQueue (except root) is always 0. And
fairscheduler only considers memory when do scheduling, so do we still need to consider vcores
here?

> In fair scheduler, intra-application container priorities affect inter-application preemption
decisions
> -------------------------------------------------------------------------------------------------------
>
>                 Key: YARN-596
>                 URL: https://issues.apache.org/jira/browse/YARN-596
>             Project: Hadoop YARN
>          Issue Type: Bug
>          Components: scheduler
>    Affects Versions: 2.0.3-alpha
>            Reporter: Sandy Ryza
>            Assignee: Sandy Ryza
>         Attachments: YARN-596.patch, YARN-596.patch, YARN-596.patch, YARN-596.patch,
YARN-596.patch
>
>
> In the fair scheduler, containers are chosen for preemption in the following way:
> All containers for all apps that are in queues that are over their fair share are put
in a list.
> The list is sorted in order of the priority that the container was requested in.
> This means that an application can shield itself from preemption by requesting it's containers
at higher priorities, which doesn't really make sense.
> Also, an application that is not over its fair share, but that is in a queue that is
over it's fair share is just as likely to have containers preempted as an application that
is over its fair share.



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Mime
View raw message