[jira] [Commented] (HBASE-10118) Major compact keeps deletes with future timestamps

["Jean-Marc Spaggiari (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HBASE-10118?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13844394#comment-13844394 ] 

Jean-Marc Spaggiari commented on HBASE-10118:
---------------------------------------------

Hum. Maybe we should make this optional? Like, hbase.hstore.time.to.purge.future.deletes=true or false?

> Major compact keeps deletes with future timestamps
> --------------------------------------------------
>
>                 Key: HBASE-10118
>                 URL: https://issues.apache.org/jira/browse/HBASE-10118
>             Project: HBase
>          Issue Type: Bug
>          Components: Compaction, Deletes, regionserver
>            Reporter: Max Lapan
>            Priority: Minor
>
> Hello!
> During migration from HBase 0.90.6 to 0.94.6 we found changed behaviour in how major compact handles delete markers with timestamps in the future. Before HBASE-4721 major compact purged deletes regardless of their timestamp. Newer versions keep them in HFile until timestamp not reached.
> I guess this happened due to new check in ScanQueryMatcher {{EnvironmentEdgeManager.currentTimeMillis() - timestamp) <= timeToPurgeDeletes}}.
> This can be worked around by specifying large negative value in {{hbase.hstore.time.to.purge.deletes}} option, but, unfortunately, negative values are pulled up to zero by Math.max in HStore.java.
> Maybe, we are trying to do something weird by specifing delete timestamp in future, but HBASE-4721 definitely breaks old behaviour we rely on.
> Steps to reproduce this:
> {code}
> put 'test', 'delmeRow', 'delme:something', 'hello'
> flush 'test'
> delete 'test', 'delmeRow', 'delme:something', 1394161431061
> flush 'test'
> major_compact 'test'
> {code}
> Before major_compact we have two hfiles with the following:
> {code}
> first:
> K: delmeRow/delme:something/1384161431061/Put/vlen=5/ts=0
> second:
> K: delmeRow/delme:something/1394161431061/DeleteColumn/vlen=0/ts=0
> {code}
> After major compact we get the following:
> {code}
> K: delmeRow/delme:something/1394161431061/DeleteColumn/vlen=0/ts=0
> {code}
> In our installation, we resolved this by removing Math.max and setting hbase.hstore.time.to.purge.deletes to Integer.MIN_VALUE, which purges delete markers, and it looks like a solution. But, maybe, there are better approach.



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