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https://issues.apache.org/jira/browse/HBASE-29265?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17952386#comment-17952386
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Daniel Roudnitsky commented on HBASE-29265:
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Looking at the updated title and description, if the issue is that the sync
client is clearing the meta cache for batch calls when it shouldn't, does the
condition for being impacted extend beyond the overloaded cluster scenario,
since we have non cache clearing exceptions that don't directly have to do with
a server being overloaded ?
> Batch calls to overloaded cluster can cause meta hotspotting
> ------------------------------------------------------------
>
> Key: HBASE-29265
> URL: https://issues.apache.org/jira/browse/HBASE-29265
> Project: HBase
> Issue Type: Improvement
> Reporter: Hernan Gelaf-Romer
> Assignee: Hernan Gelaf-Romer
> Priority: Major
> Labels: pull-request-available
>
> Somewhat related to https://issues.apache.org/jira/browse/HBASE-27487
>
> In HBase 2.X, the AsyncRequestFutureImpl will clear the meta cache if it
> receives a batch call that fails to execute. When AsyncRequestFutureImpl
> receives an exception from a multi call, it will call receiveGlobalFailure
> and force a meta cache clear, even if the exception received does not usually
> trigger meta cache clears.
>
> This can cause issues on HBase clusters that are currently overloaded. If a
> server is overloaded, it can force clients to repeatedly clear meta cache,
> causing a meta hotspot, which further slows down queries. I'm not entirely
> sure why we force meta cache clears, but I think we should exempt exceptions
> that indicate that a server is overloaded from clearing the meta cache.
>
> I'm also open to only clearing the meta cache if the exception received is a
> cache clearing exception, but I'd need to make sure this doesn't invalidate
> some assumptions made when the code was first written.
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