[
https://issues.apache.org/jira/browse/YARN-7655?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16357553#comment-16357553
]
Hudson commented on YARN-7655:
------------------------------
SUCCESS: Integrated in Jenkins build Hadoop-trunk-Commit #13636 (See
[https://builds.apache.org/job/Hadoop-trunk-Commit/13636/])
YARN-7655. Avoid AM preemption caused by RRs for specific nodes or (yufei: rev
1bc03ddf97f3f0e0ecc1b00217438d3c91d29be5)
* (edit)
hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FSPreemptionThread.java
* (edit)
hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairSchedulerPreemption.java
> Avoid AM preemption caused by RRs for specific nodes or racks
> -------------------------------------------------------------
>
> Key: YARN-7655
> URL: https://issues.apache.org/jira/browse/YARN-7655
> Project: Hadoop YARN
> Issue Type: Improvement
> Components: fairscheduler
> Affects Versions: 3.0.0
> Reporter: Steven Rand
> Assignee: Steven Rand
> Priority: Major
> Fix For: 3.1.0
>
> Attachments: YARN-7655-001.patch, YARN-7655-002.patch,
> YARN-7655-003.patch, YARN-7655-004.patch
>
>
> We frequently see AM preemptions when
> {{starvedApp.getStarvedResourceRequests()}} in
> {{FSPreemptionThread#identifyContainersToPreempt}} includes one or more RRs
> that request containers on a specific node. Since this causes us to only
> consider one node to preempt containers on, the really good work that was
> done in YARN-5830 doesn't save us from AM preemption. Even though there might
> be multiple nodes on which we could preempt enough non-AM containers to
> satisfy the app's starvation, we often wind up preempting one or more AM
> containers on the single node that we're considering.
> A proposed solution is that if we're going to preempt one or more AM
> containers for an RR that specifies a node or rack, then we should instead
> expand the search space to consider all nodes. That way we take advantage of
> YARN-5830, and only preempt AMs if there's no alternative. I've attached a
> patch with an initial implementation of this. We've been running it on a few
> clusters, and have seen AM preemptions drop from double-digit occurrences on
> many days to zero.
> Of course, the tradeoff is some loss of locality, since the starved app is
> less likely to be allocated resources at the most specific locality level
> that it asked for. My opinion is that this tradeoff is worth it, but
> interested to hear what others think as well.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: yarn-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: yarn-issues-h...@hadoop.apache.org
