[
https://issues.apache.org/jira/browse/YARN-9770?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16917528#comment-16917528
]
Wangda Tan commented on YARN-9770:
----------------------------------
[~jhung] , I understand the use case, however I think this will break
preemption. When there're two queues A and B. A uses more than guaranteed and
have pending resource, B uses less than guaranteed and has pending resource.
Before this patch, any resources preempted from A can be guarateed to consumed
by B. However, after this patch, it is possible that A get preference
allocation order and get the preempted resource again.
> Create a queue ordering policy which picks child queues with equal probability
> ------------------------------------------------------------------------------
>
> Key: YARN-9770
> URL: https://issues.apache.org/jira/browse/YARN-9770
> Project: Hadoop YARN
> Issue Type: Improvement
> Reporter: Jonathan Hung
> Assignee: Jonathan Hung
> Priority: Major
> Labels: release-blocker
> Attachments: YARN-9770.001.patch, YARN-9770.002.patch,
> YARN-9770.003.patch
>
>
> Ran some simulations with the default queue_utilization_ordering_policy:
> An underutilized queue which receives an application with many (thousands)
> resource requests will hog scheduler allocations for a long time (on the
> order of a minute). In the meantime apps are getting submitted to all other
> queues, which increases activeUsers in these queues, which drops user limit
> in these queues to small values if minimum-user-limit-percent is configured
> to small values (e.g. 10%).
> To avoid this issue, we assign to queues with equal probability, to avoid
> scenarios where queues don't get allocations for a long time.
--
This message was sent by Atlassian Jira
(v8.3.2#803003)
---------------------------------------------------------------------
To unsubscribe, e-mail: yarn-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: yarn-issues-h...@hadoop.apache.org
