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https://issues.apache.org/jira/browse/HBASE-14205?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14682288#comment-14682288
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stack commented on HBASE-14205:
-------------------------------
bq. We couldn't the this feature in 1.0 release line, as it breaks operational
compatibility.
[~srikanth235] Sorry. You saying can't remove in 1.0 though it a "performance
bottleneck"? Can't we default it off? Seems a little unfair having all pay the
perf cost for a metric read by a few.
> RegionCoprocessorHost System.nanoTime() performance bottleneck
> --------------------------------------------------------------
>
> Key: HBASE-14205
> URL: https://issues.apache.org/jira/browse/HBASE-14205
> Project: HBase
> Issue Type: Bug
> Reporter: Jan Van Besien
> Priority: Critical
> Fix For: 2.0.0, 1.2.0, 1.3.0
>
>
> The tracking of execution time of coprocessor methods introduced in
> HBASE-11516 introduces 2 calls to System.nanoTime() per coprocessor method
> per coprocessor. This is resulting in a serious performance bottleneck in
> certain scenarios.
> For example consider the scenario where many rows are being ingested (PUT) in
> a table which has multiple coprocessors (we have up to 20 coprocessors). This
> results in 8 extra calls to System.nanoTime() per coprocessor (prePut,
> postPut, postStartRegionOperation and postCloseRegionOperation) which has in
> total (i.e. times 20) been seen to result in a 50% increase of execution time.
> I think it is generally considered bad practice to measure execution times on
> such a small scale (per single operation). Also note that measurements are
> taken even for coprocessors that do not even have an actual implementation
> for certain operations, making the problem worse.
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