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https://issues.apache.org/jira/browse/HBASE-2990?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12914235#action_12914235
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Ted Yu commented on HBASE-2990:
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Store.getLowestTimestamp() checks timestamp from files. This check is not
sufficient for major compaction to work - due to minor compactions within the
past day.
One solution is to store timestamp of most recent major compaction in a file in
the same directory as filesToCompact.get(0).
> It's possible for regions to not be major compacted for more than
> hbase.hregion.majorcompaction
> -----------------------------------------------------------------------------------------------
>
> Key: HBASE-2990
> URL: https://issues.apache.org/jira/browse/HBASE-2990
> Project: HBase
> Issue Type: Bug
> Reporter: Jean-Daniel Cryans
> Priority: Critical
> Fix For: 0.90.0
>
>
> This is something I've seen here since we upgraded to 0.89 since Gets are now
> Scans, although I don't currently have any strong evidence that it wasn't
> happening in 0.20.
> I saw this when we began getting alerts on the frontend that some requests
> were taking more than 8 seconds to complete. Even getting a value could take
> more than 3 minutes in the shell. The first thing I did was major compacting
> the table that was slow and the problem went away immediately. Looking in the
> logs, it seems the compaction transformed 2 files of (total) 550MB into
> 5.2MB. Looking back in the logs for September, it appears that that table was
> never major compacted and was slowly growing everyday. Some more grepping
> around showed that quite a few regions were never major compacted.
> I'm still looking at the code, but the issue seems to be that the minor
> compactions are always happening on all store files more than once per day on
> certain regions, meaning that the oldest timestamp is always smaller than
> hbase.hregion.majorcompaction and major compactions are never triggered.
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