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https://issues.apache.org/jira/browse/HBASE-15513?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15206701#comment-15206701
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stack commented on HBASE-15513:
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bq. Stack Can you explain how not reusing buffers can improve performance and
latency? I am just trying to understand magic physics of "allocate buffer on
every request" approach.
See where Elliott wanted a flag to disable pooled bytebuffers because it put a
spanner in his G1GC works; HBASE-14942. On the face of it 'reuse' should be
always better but the Elliott issue and a new one coming in that [~ram_krish]
and [~anoop.hbase] are studying a case where resuse seems to make for less GC
but the GC runs for longer, would seem to indicate that 'reuse' is not panacea.
My suggestion is we do some basic testing to verify no side effects..... Do it
now as part of check-in rather than let some poor sod down the line figure
there an unexpected regression (and have to figure it without context). See the
original issue too where there is discussion on when to enable the pool.
> hbase.hregion.memstore.chunkpool.maxsize is 0.0 by default
> ----------------------------------------------------------
>
> Key: HBASE-15513
> URL: https://issues.apache.org/jira/browse/HBASE-15513
> Project: HBase
> Issue Type: Improvement
> Affects Versions: 2.0.0
> Reporter: Vladimir Rodionov
> Assignee: Vladimir Rodionov
> Fix For: 2.0.0
>
>
> That results in excessive MemStoreLAB chunk allocations because we can not
> reuse them. Not sure, why it has been disabled, by default. May be the code
> has not been tested well?
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