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https://issues.apache.org/jira/browse/YARN-2154?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14123380#comment-14123380
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Karthik Kambatla commented on YARN-2154:
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At an abstract level, I propose the following:
# For each queue, the child {{Schedulable}}s should be sorted in the ascending
order of (desiredShare - fairShare). In case of FSLeafQueue, this corresponds
to running applications.
# Add {{FSQueue#estimateStarvation(List<FSAppAttempt>)}} to find enough
applications, considering minshare and fairshare starvation in that order. Or,
should we have two methods, one for each kind of starvation.
# For a starved queue, we do a depth-first traversal (in the order of
deprivation) to find these applications. If none of child queues/applications
are under their shares, we pick the application (if it exists) with a positive
demand and least over its share.
# Once the application list is computed, we traverse through the
ResourceRequests (ordered first by application, second by priority) and preempt
any matching containers currently assigned to an application over its share.
# As a follow up, we can consider looking at this application list first at
schedule time.
Thoughts?
> FairScheduler: Improve preemption to preempt only those containers that would
> satisfy the incoming request
> ----------------------------------------------------------------------------------------------------------
>
> Key: YARN-2154
> URL: https://issues.apache.org/jira/browse/YARN-2154
> Project: Hadoop YARN
> Issue Type: Improvement
> Components: fairscheduler
> Affects Versions: 2.4.0
> Reporter: Karthik Kambatla
> Assignee: Karthik Kambatla
> Priority: Critical
>
> Today, FairScheduler uses a spray-gun approach to preemption. Instead, it
> should only preempt resources that would satisfy the incoming request.
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