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https://issues.apache.org/jira/browse/YARN-8789?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16709605#comment-16709605
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Wilfred Spiegelenburg commented on YARN-8789:
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First: I would expect that the change would be fully tested and thus the
behaviour with a limited queue would be known and described. Task failures are
probably more acceptable. Are we really still seeing them with the change from
MAPREDUCE-5124 applied? If not then making this change is not really warranted.
Before we go further and make a change like this I would also test the
behaviour. What happens when the queue is full. Looking at the patch there is
far more change than needed: the current queue can be limited and just that
change would be far less impactful. The logic for taking an event is also
changed which I don't think is needed either. Going back to just the basic
change of limiting the queue after we find that it is needed would be a better
approach.
Based on that quick analysis I would say this is not an acceptable change in
its current form.
> Add BoundedQueue to AsyncDispatcher
> -----------------------------------
>
> Key: YARN-8789
> URL: https://issues.apache.org/jira/browse/YARN-8789
> Project: Hadoop YARN
> Issue Type: Improvement
> Components: applications
> Affects Versions: 3.2.0
> Reporter: BELUGA BEHR
> Assignee: BELUGA BEHR
> Priority: Major
> Attachments: YARN-8789.1.patch, YARN-8789.10.patch,
> YARN-8789.12.patch, YARN-8789.14.patch, YARN-8789.2.patch, YARN-8789.3.patch,
> YARN-8789.4.patch, YARN-8789.5.patch, YARN-8789.6.patch, YARN-8789.7.patch,
> YARN-8789.7.patch, YARN-8789.8.patch, YARN-8789.9.patch
>
>
> I recently came across a scenario where an MR ApplicationMaster was failing
> with an OOM exception. It had many thousands of Mappers and thousands of
> Reducers. It was noted that in the logging that the event-queue of
> {{AsyncDispatcher}} had a very large number of item in it and was seemingly
> never decreasing.
> I started looking at the code and thought it could use some clean up,
> simplification, and the ability to specify a bounded queue so that any
> incoming events are throttled until they can be processed. This will protect
> the ApplicationMaster from a flood of events.
> Logging Message:
> Size of event-queue is xxx
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