[
https://issues.apache.org/jira/browse/HBASE-7868?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13580347#comment-13580347
]
Lars Hofhansl commented on HBASE-7868:
--------------------------------------
Did some scan testing... Scanning 20m KVs through the highlevel scan api, such
that all KVs are touched but filtered by a Filter at the server and all data in
the block cache (so we can test tight scan performance).
I do see an improvement when the schemaMetrics calls are commented out in
HFileReaderV2.
The scan time when from ~11.9 to ~11.6, so about a 2.5% improvement.
As Andy points out, we need to keep these metrics around and HBASE-6852
improved things (cache hits are maintained lazily), there might be further
improvements that we can do.
> 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: hfileperf-graphs.png
>
>
> 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.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
