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https://issues.apache.org/jira/browse/YARN-611?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14118378#comment-14118378
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Vinod Kumar Vavilapalli commented on YARN-611:
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bq. I'm not sure whether it is really necessary to have a completely standalone
proto messages for ApplicationRetryPolicy's implementations.
The current proposal is that way due to a limitation of Protocol buffers: we
don't have first-class unions. May be we can cleanup the java API to use a
union and translate it underneath. We need the abstraction though, to support
more such policies in the future.
bq. Maybe we can make use a thread pool, or even have a single thread (e.g., a
service of RM) to take care of all the apps' reset windows.
+1 for this. We shouldn't be needing more than one thread to start with.
bq. Affecting RMStateStore
For now, we can simply forget the window statistics on RM reboot - that is a
reasonable start..
> Add an AM retry count reset window to YARN RM
> ---------------------------------------------
>
> Key: YARN-611
> URL: https://issues.apache.org/jira/browse/YARN-611
> Project: Hadoop YARN
> Issue Type: Bug
> Components: resourcemanager
> Affects Versions: 2.0.3-alpha
> Reporter: Chris Riccomini
> Assignee: Xuan Gong
> Attachments: YARN-611.1.patch, YARN-611.2.patch, YARN-611.3.patch,
> YARN-611.4.patch, YARN-611.4.rebase.patch, YARN-611.5.patch
>
>
> YARN currently has the following config:
> yarn.resourcemanager.am.max-retries
> This config defaults to 2, and defines how many times to retry a "failed" AM
> before failing the whole YARN job. YARN counts an AM as failed if the node
> that it was running on dies (the NM will timeout, which counts as a failure
> for the AM), or if the AM dies.
> This configuration is insufficient for long running (or infinitely running)
> YARN jobs, since the machine (or NM) that the AM is running on will
> eventually need to be restarted (or the machine/NM will fail). In such an
> event, the AM has not done anything wrong, but this is counted as a "failure"
> by the RM. Since the retry count for the AM is never reset, eventually, at
> some point, the number of machine/NM failures will result in the AM failure
> count going above the configured value for
> yarn.resourcemanager.am.max-retries. Once this happens, the RM will mark the
> job as failed, and shut it down. This behavior is not ideal.
> I propose that we add a second configuration:
> yarn.resourcemanager.am.retry-count-window-ms
> This configuration would define a window of time that would define when an AM
> is "well behaved", and it's safe to reset its failure count back to zero.
> Every time an AM fails the RmAppImpl would check the last time that the AM
> failed. If the last failure was less than retry-count-window-ms ago, and the
> new failure count is > max-retries, then the job should fail. If the AM has
> never failed, the retry count is < max-retries, or if the last failure was
> OUTSIDE the retry-count-window-ms, then the job should be restarted.
> Additionally, if the last failure was outside the retry-count-window-ms, then
> the failure count should be set back to 0.
> This would give developers a way to have well-behaved AMs run forever, while
> still failing mis-behaving AMs after a short period of time.
> I think the work to be done here is to change the RmAppImpl to actually look
> at app.attempts, and see if there have been more than max-retries failures in
> the last retry-count-window-ms milliseconds. If there have, then the job
> should fail, if not, then the job should go forward. Additionally, we might
> also need to add an endTime in either RMAppAttemptImpl or
> RMAppFailedAttemptEvent, so that the RmAppImpl can check the time of the
> failure.
> Thoughts?
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