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https://issues.apache.org/jira/browse/HBASE-7868?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13580721#comment-13580721
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Lars Hofhansl commented on HBASE-7868:
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I think PE needs some TLC.
In it's current form it is not that useful (to say it bluntly), and it is 100%
not obvious how to use it (I had to look at the source code to figure out what
the filterScan test is supposed to do).
At the very least we should add to the help text that one should seed the table
first with a SequentialWriteTest picking the right of rows. The HBase wiki
seems to imply that SequentialWriteTest is automatically run unless we run it
in M/R mode, but it looks like that is not true.
The help text does say to run FilterScanTest with --rows=20, not entirely sure
why.
> HFile performance regression between 0.92 and 0.94
> --------------------------------------------------
>
> Key: HBASE-7868
> URL: https://issues.apache.org/jira/browse/HBASE-7868
> Project: HBase
> Issue Type: Bug
> Components: io
> Affects Versions: 0.94.5
> Reporter: Matteo Bertozzi
> Assignee: Matteo Bertozzi
> Fix For: 0.94.6
>
> Attachments: FilteredScan.png, hfileperf-graphs.png,
> performances.pdf, performances.pdf
>
>
> By HFilePerformanceEvaluation seems that 0.94 is slower then 0.92
> Looking at the profiler for the Scan path, seems that most of the time,
> compared to 92, is spent in the metrics dictionary lookup. [~eclark] pointed
> out the new per family/block metrics.
> By commenting the metrics call in HFileReaderV2, the performance seems to get
> better, but maybe metrics is not the only problem.
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