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https://issues.apache.org/jira/browse/HBASE-13420?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14507560#comment-14507560
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Andrew Purtell commented on HBASE-13420:
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bq. Seems not worth it to me, unless John Leach has a more specific use case
where we'd see a larger difference.
I think you misunderstand Lars. Here are the benchmarks that matter:
https://issues.apache.org/jira/browse/HBASE-13420?focusedCommentId=14486865&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14486865
. This is on top of John's original report indicating a problem with the
BlockingQueues holding up threads in his test case.
You then asked for more information. I ran two macro-benchmarks to see if
there's any perf hit. Here
https://issues.apache.org/jira/browse/HBASE-13420?focusedCommentId=14504156&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14504156
and here
https://issues.apache.org/jira/browse/HBASE-13420?focusedCommentId=14506064&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14506064
. I'm not seeing a significant degradation. The purpose of these last two
tests were not to show some kind of improvement.
> RegionEnvironment.offerExecutionLatency Blocks Threads under Heavy Load
> -----------------------------------------------------------------------
>
> Key: HBASE-13420
> URL: https://issues.apache.org/jira/browse/HBASE-13420
> Project: HBase
> Issue Type: Improvement
> Reporter: John Leach
> Assignee: Andrew Purtell
> Fix For: 2.0.0, 1.1.0, 0.98.13, 1.0.2
>
> Attachments: 1M-0.98.12.svg, 1M-0.98.13-SNAPSHOT.svg,
> HBASE-13420.patch, HBASE-13420.txt, hbase-13420.tar.gz,
> offerExecutionLatency.tiff
>
> Original Estimate: 3h
> Remaining Estimate: 3h
>
> The ArrayBlockingQueue blocks threads for 20s during a performance run
> focusing on creating numerous small scans.
> I see a buffer size of (100)
> private final BlockingQueue<Long> coprocessorTimeNanos = new
> ArrayBlockingQueue<Long>(
> LATENCY_BUFFER_SIZE);
> and then I see a drain coming from
> MetricsRegionWrapperImpl with 45 second executor
> HRegionMetricsWrapperRunable
> RegionCoprocessorHost#getCoprocessorExecutionStatistics()
> RegionCoprocessorHost#getExecutionLatenciesNanos()
> Am I missing something?
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