Max Lapan created HBASE-10118:
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Summary: 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.
It is very possible that 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.
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