[jira] [Created] (HBASE-14205) RegionCoprocessorHost System.nanoTime() performance bottleneck

["Jan Van Besien (JIRA)" <ji...@apache.org>]

Jan Van Besien created HBASE-14205:
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             Summary: 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


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.



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