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Jean-Daniel Cryans resolved HBASE-4792. --------------------------------------- Resolution: Fixed Hadoop Flags: Reviewed Committed to branch and trunk, thanks for looking at my code Stack. > SplitRegionHandler doesn't care if it deletes the znode or not, leaves the > parent region stuck offline > ------------------------------------------------------------------------------------------------------ > > Key: HBASE-4792 > URL: https://issues.apache.org/jira/browse/HBASE-4792 > Project: HBase > Issue Type: Bug > Affects Versions: 0.92.0 > Reporter: Jean-Daniel Cryans > Assignee: Jean-Daniel Cryans > Priority: Critical > Fix For: 0.92.0, 0.94.0 > > Attachments: HBASE-4792-0.92.patch > > > Saw this on a little test cluster, really easy to trigger. > First the master log: > {quote} > 2011-11-15 22:28:57,900 DEBUG > org.apache.hadoop.hbase.master.handler.SplitRegionHandler: Handling SPLIT > event for e5be6551c8584a6a1065466e520faf4e; deleting node > 2011-11-15 22:28:57,900 DEBUG org.apache.hadoop.hbase.zookeeper.ZKAssign: > master:62003-0x132f043bbde08c1 Deleting existing unassigned node for > e5be6551c8584a6a1065466e520faf4e that is in expected state RS_ZK_REGION_SPLIT > 2011-11-15 22:28:57,975 WARN org.apache.hadoop.hbase.zookeeper.ZKAssign: > master:62003-0x132f043bbde08c1 Attempting to delete unassigned node in > RS_ZK_REGION_SPLIT state but after verifying state, we got a version mismatch > 2011-11-15 22:28:57,975 INFO > org.apache.hadoop.hbase.master.handler.SplitRegionHandler: Handled SPLIT > report); > parent=TestTable,0001355346,1321396080924.e5be6551c8584a6a1065466e520faf4e. > daughter > a=TestTable,0001355346,1321396132414.df9b549eb594a1f8728608a2a431224a.daughter > b=TestTable,0001368082,1321396132414.de861596db4337dc341138f26b9c8bc2. > ... > 2011-11-15 22:28:58,052 DEBUG > org.apache.hadoop.hbase.master.AssignmentManager: Handling > transition=RS_ZK_REGION_SPLIT, server=sv4r28s44,62023,1321395865619, > region=e5be6551c8584a6a1065466e520faf4e > 2011-11-15 22:28:58,052 WARN > org.apache.hadoop.hbase.master.AssignmentManager: Region > e5be6551c8584a6a1065466e520faf4e not found on server > sv4r28s44,62023,1321395865619; failed processing > 2011-11-15 22:28:58,052 WARN > org.apache.hadoop.hbase.master.AssignmentManager: Received SPLIT for region > e5be6551c8584a6a1065466e520faf4e from server sv4r28s44,62023,1321395865619 > but it doesn't exist anymore, probably already processed its split > (repeated forever) > {quote} > The master processes the split but when it calls ZKAssign.deleteNode it > doesn't check the boolean that's returned. In this case it was false. So for > the master the split was completed, but for the region server it's another > story: > {quote} > 2011-11-15 22:28:57,661 DEBUG org.apache.hadoop.hbase.zookeeper.ZKAssign: > regionserver:62023-0x132f043bbde08d3 Attempting to transition node > e5be6551c8584a6a1065466e520faf4e from RS_ZK_REGION_SPLITTING to > RS_ZK_REGION_SPLIT > 2011-11-15 22:28:57,775 DEBUG org.apache.hadoop.hbase.zookeeper.ZKAssign: > regionserver:62023-0x132f043bbde08d3 Successfully transitioned node > e5be6551c8584a6a1065466e520faf4e from RS_ZK_REGION_SPLITTING to > RS_ZK_REGION_SPLIT > 2011-11-15 22:28:57,775 INFO > org.apache.hadoop.hbase.regionserver.SplitTransaction: Still waiting on the > master to process the split for e5be6551c8584a6a1065466e520faf4e > 2011-11-15 22:28:57,876 DEBUG org.apache.hadoop.hbase.zookeeper.ZKAssign: > regionserver:62023-0x132f043bbde08d3 Attempting to transition node > e5be6551c8584a6a1065466e520faf4e from RS_ZK_REGION_SPLIT to RS_ZK_REGION_SPLIT > 2011-11-15 22:28:57,967 DEBUG org.apache.hadoop.hbase.zookeeper.ZKAssign: > regionserver:62023-0x132f043bbde08d3 Successfully transitioned node > e5be6551c8584a6a1065466e520faf4e from RS_ZK_REGION_SPLIT to RS_ZK_REGION_SPLIT > 2011-11-15 22:28:58,067 DEBUG org.apache.hadoop.hbase.zookeeper.ZKAssign: > regionserver:62023-0x132f043bbde08d3 Attempting to transition node > e5be6551c8584a6a1065466e520faf4e from RS_ZK_REGION_SPLIT to RS_ZK_REGION_SPLIT > 2011-11-15 22:28:58,108 DEBUG org.apache.hadoop.hbase.zookeeper.ZKAssign: > regionserver:62023-0x132f043bbde08d3 Successfully transitioned node > e5be6551c8584a6a1065466e520faf4e from RS_ZK_REGION_SPLIT to RS_ZK_REGION_SPLIT > (printed forever) > {quote} > Since the znode isn't really deleted, it thinks the master just haven't got > to process its region thus waits which leaves the region *unavailable*. > We need to just retry the delete master-side ASAP since the RS will wait > 100ms between retries. > At the same time, it would be nice if ZKAssign.deleteNode always printed out > the name of the region in its messages because it took me a while to see that > the delete didn't take affect while looking at a grep. -- This message is automatically generated by JIRA. 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