Details
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Bug
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Status: Resolved
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Major
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Resolution: Fixed
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2.2.4
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None
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- HDFS 3.1.3
- HBase 2.1.4
- OpenJDK 8
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Reviewed
Description
Under the following scenario region directories in HDFS can be recreated with only recovered.edits in them:
- Create table "test"
- Put into "test"
- Delete table "test"
- Create table "test" again
- Crash the regionserver to which the put has went to force the WAL replay
- Region directory in old table is recreated in new table
- hbase hbck returns inconsistency
This appears to happen due to the fact that WALs are not cleaned up once a table is deleted and they still contain the edits from old table. I've tried wal_roll command on the regionserver before crashing it, but it doesn't seem to help as under some circumstances there are still WAL files around. The only solution that works consistently is to restart regionserver before creating the table at step 4 because that triggers log cleanup on startup: https://github.com/apache/hbase/blob/f3ee9b8aa37dd30d34ff54cd39fb9b4b6d22e683/hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/store/wal/WALProcedureStore.java#L508
Truncating a table also would be a workaround by in our case it's a no-go as we create and delete tables in our tests which run back to back (create table in the beginning of the test and delete in the end of the test).
A nice option in our case would be to provide hbase shell utility to force clean up of log files manually as I realize that it's not really viable to clean all of those up every time some table is removed.