[
https://issues.apache.org/jira/browse/HBASE-2770?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12887962#action_12887962
]
Dave Latham commented on HBASE-2770:
------------------------------------
It was definitely a headache for us during our data center migration, but I've
got no immediate need for it if you're wanting to get 0.20.6 out and this is
blocking the way.
You can put a cluster into read-only mode and make sure that hbase doesn't
touch the store files while copying them away by setting
hbase.hregion.majorcompaction to a very high value to workaround this issue.
> Major compactions from shell may not major compact all families
> ---------------------------------------------------------------
>
> Key: HBASE-2770
> URL: https://issues.apache.org/jira/browse/HBASE-2770
> Project: HBase
> Issue Type: Bug
> Affects Versions: 0.20.4
> Reporter: Dave Latham
> Priority: Critical
> Fix For: 0.20.6, 0.90.0
>
>
> As part of a data center migration, I initiated a major_compaction request on
> all tables from the shell. A few hours later, all the region servers in the
> cluster appeared to have completed the compactions and all compactionQueue
> metrics were back to 0. However, some column families of some regions had
> not actually done a major compaction.
> Digging through logs and code, it looks like the following happened. The
> shell makes a major compaction request which sets
> HRegion.forceMajorCompaction to true for every region. Periodically, the
> HRegionServer.MajorCompactionChecker checks to see if a major compaction is
> needed in any family's store. If so, calls
> CompactSplitThread.compactionRequested which ends up setting the region
> forceMajorCompaction to false, even if it is already in the compaction queue
> and set to true. Then, when that region comes off the queue to be compacted,
> each family/store separately checks for whether it should do a major
> compaction, so some families may not do so.
> (This is not good if, for example, you're doing a DistCp of the hbase dir and
> later on the cluster decides to do a compaction on those files and deletes
> ones the DistCp job is looking for, causing it to fail.)
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
