[HBASE-6088] Region splitting not happened for long time due to ZK exception while creating RS_ZK_SPLITTING node

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.94.0
• Fix Version/s: 0.94.1, 0.95.0
• Hadoop Flags: Reviewed
• Assignee: rajeshbabu
• Reporter: Gopinathan A
• Created: 24/May/12 13:32
• Updated: 26/Feb/13 08:15
• Resolved: 29/May/12 16:21

Description

Region splitting not happened for long time due to ZK exception while creating RS_ZK_SPLITTING node

2012-05-24 01:45:41,363 INFO org.apache.zookeeper.ClientCnxn: Client session timed out, have not heard from server in 26668ms for sessionid 0x1377a75f41d0012, closing socket connection and attempting reconnect
2012-05-24 01:45:41,464 WARN org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper: Possibly transient ZooKeeper exception: org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /hbase/unassigned/bd1079bf948c672e493432020dc0e144

2012-05-24 01:45:43,300 DEBUG org.apache.hadoop.hbase.regionserver.wal.HLog: cleanupCurrentWriter  waiting for transactions to get synced  total 189377 synced till here 189365
2012-05-24 01:45:48,474 INFO org.apache.hadoop.hbase.regionserver.SplitRequest: Running rollback/cleanup of failed split of ufdr,011365398471659,1337823505339.bd1079bf948c672e493432020dc0e144.; Failed setting SPLITTING znode on ufdr,011365398471659,1337823505339.bd1079bf948c672e493432020dc0e144.
java.io.IOException: Failed setting SPLITTING znode on ufdr,011365398471659,1337823505339.bd1079bf948c672e493432020dc0e144.
	at org.apache.hadoop.hbase.regionserver.SplitTransaction.createDaughters(SplitTransaction.java:242)
	at org.apache.hadoop.hbase.regionserver.SplitTransaction.execute(SplitTransaction.java:450)
	at org.apache.hadoop.hbase.regionserver.SplitRequest.run(SplitRequest.java:67)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)
Caused by: org.apache.zookeeper.KeeperException$BadVersionException: KeeperErrorCode = BadVersion for /hbase/unassigned/bd1079bf948c672e493432020dc0e144
	at org.apache.zookeeper.KeeperException.create(KeeperException.java:115)
	at org.apache.zookeeper.KeeperException.create(KeeperException.java:51)
	at org.apache.zookeeper.ZooKeeper.setData(ZooKeeper.java:1246)
	at org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper.setData(RecoverableZooKeeper.java:321)
	at org.apache.hadoop.hbase.zookeeper.ZKUtil.setData(ZKUtil.java:659)
	at org.apache.hadoop.hbase.zookeeper.ZKAssign.transitionNode(ZKAssign.java:811)
	at org.apache.hadoop.hbase.zookeeper.ZKAssign.transitionNode(ZKAssign.java:747)
	at org.apache.hadoop.hbase.regionserver.SplitTransaction.transitionNodeSplitting(SplitTransaction.java:919)
	at org.apache.hadoop.hbase.regionserver.SplitTransaction.createNodeSplitting(SplitTransaction.java:869)
	at org.apache.hadoop.hbase.regionserver.SplitTransaction.createDaughters(SplitTransaction.java:239)
	... 5 more
2012-05-24 01:45:48,476 INFO org.apache.hadoop.hbase.regionserver.SplitRequest: Successful rollback of failed split of ufdr,011365398471659,1337823505339.bd1079bf948c672e493432020dc0e144.

2012-05-24 01:47:28,141 ERROR org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper: Node /hbase/unassigned/bd1079bf948c672e493432020dc0e144 already exists and this is not a retry
2012-05-24 01:47:28,142 INFO org.apache.hadoop.hbase.regionserver.SplitRequest: Running rollback/cleanup of failed split of ufdr,011365398471659,1337823505339.bd1079bf948c672e493432020dc0e144.; Failed create of ephemeral /hbase/unassigned/bd1079bf948c672e493432020dc0e144
java.io.IOException: Failed create of ephemeral /hbase/unassigned/bd1079bf948c672e493432020dc0e144
	at org.apache.hadoop.hbase.regionserver.SplitTransaction.createNodeSplitting(SplitTransaction.java:865)
	at org.apache.hadoop.hbase.regionserver.SplitTransaction.createDaughters(SplitTransaction.java:239)
	at org.apache.hadoop.hbase.regionserver.SplitTransaction.execute(SplitTransaction.java:450)
	at org.apache.hadoop.hbase.regionserver.SplitRequest.run(SplitRequest.java:67)

Due to the above exception, region splitting was failing contineously more than 5hrs

Issue Links

• relates to: HBASE-7103 Need to fail split if SPLIT znode is deleted even before the split is completed.