Andrey Elenskiy created HBASE-24189:
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Summary: Regionserver recreates region folders in HDFS after
replaying WAL with removed table entries
Key: HBASE-24189
URL: https://issues.apache.org/jira/browse/HBASE-24189
Project: HBase
Issue Type: Bug
Components: regionserver, wal
Affects Versions: 2.2.4
Environment: * HDFS 3.1.3
* HBase 2.1.4
* OpenJDK 8
Reporter: Andrey Elenskiy
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|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.
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