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https://issues.apache.org/jira/browse/HBASE-14205?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jan Van Besien updated HBASE-14205:
-----------------------------------
Description:
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.
was:
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 row (prePut, postPut,
postStartRegionOperation and postCloseRegionOperation) which has 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.
> 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
>
> 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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