[HBASE-11282] Load balancer may move a region which is participating in snapshot

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Later
• Assignee: Unassigned
• Reporter: Ted Yu
• Created: 02/Jun/14 16:09
• Updated: 17/Jun/22 05:50
• Resolved: 04/Jun/14 00:39

Description

The region was tableone,,1394495094967.289ebdee6adf0a3b9c2bbcbe2ff522e7.
From master log:

2014-03-10 23:48:09,035 DEBUG [AM.ZK.Worker-pool2-t42] master.AssignmentManager: Found an existing plan for tableone,,1394495094967.289ebdee6adf0a3b9c2bbcbe2ff522e7.       destination server is h2-ubuntu12-sec-1394425849-hbase-4.cs1cloud.internal,60020,1394494963812 accepted as a dest server = true
2014-03-10 23:48:09,035 DEBUG [AM.ZK.Worker-pool2-t42] master.AssignmentManager: Using pre-existing plan for tableone,,1394495094967.289ebdee6adf0a3b9c2bbcbe2ff522e7.;     plan=hri=tableone,,1394495094967.289ebdee6adf0a3b9c2bbcbe2ff522e7., src=h2-ubuntu12-sec-1394425849-hbase-9.cs1cloud.internal,60020,1394494962165, dest=h2-ubuntu12-sec-     1394425849-hbase-4.cs1cloud.internal,60020,1394494963812
2014-03-10 23:48:09,035 INFO  [AM.ZK.Worker-pool2-t42] master.RegionStates: Transitioned {289ebdee6adf0a3b9c2bbcbe2ff522e7 state=CLOSED, ts=1394495289035, server=h2-       ubuntu12-sec-1394425849-hbase-9.cs1cloud.internal,60020,1394494962165} to {289ebdee6adf0a3b9c2bbcbe2ff522e7 state=OFFLINE, ts=1394495289035, server=h2-ubuntu12-sec-        1394425849-hbase-9.cs1cloud.internal,60020,1394494962165}
2014-03-10 23:48:09,035 DEBUG [AM.ZK.Worker-pool2-t42] zookeeper.ZKAssign: master:60000-0x244aa9920190b04, quorum=h2-ubuntu12-sec-1394425849-hbase-8.cs1cloud.internal:2181,h2-ubuntu12-sec-1394425849-hbase-1.cs1cloud.internal:2181,h2-ubuntu12-sec-1394425849-hbase-4.cs1cloud.internal:2181, baseZNode=/hbase Creating (or updating) unassigned     node 289ebdee6adf0a3b9c2bbcbe2ff522e7 with OFFLINE state
2014-03-10 23:48:09,044 INFO  [AM.ZK.Worker-pool2-t42] master.AssignmentManager: Assigning tableone,,1394495094967.289ebdee6adf0a3b9c2bbcbe2ff522e7. to h2-ubuntu12-sec-    1394425849-hbase-4.cs1cloud.internal,60020,1394494963812

From hbase-hbase-regionserver-h2-ubuntu12-sec-1394425849-hbase-9.log :

2014-03-10 23:48:08,487 WARN  [member: 'h2-ubuntu12-sec-1394425849-hbase-9.cs1cloud.internal,60020,1394494962165' subprocedure-pool1-thread-1] snapshot.                    RegionServerSnapshotManager: Got Exception in SnapshotSubprocedurePool
java.util.concurrent.ExecutionException: org.apache.hadoop.hbase.NotServingRegionException: tableone,,1394495094967.289ebdee6adf0a3b9c2bbcbe2ff522e7. is closing
  at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:222)
  at java.util.concurrent.FutureTask.get(FutureTask.java:83)
  at org.apache.hadoop.hbase.regionserver.snapshot.RegionServerSnapshotManager$SnapshotSubprocedurePool.waitForOutstandingTasks(RegionServerSnapshotManager.java:325)
  at org.apache.hadoop.hbase.regionserver.snapshot.FlushSnapshotSubprocedure.flushSnapshot(FlushSnapshotSubprocedure.java:118)
  at org.apache.hadoop.hbase.regionserver.snapshot.FlushSnapshotSubprocedure.insideBarrier(FlushSnapshotSubprocedure.java:137)
  at org.apache.hadoop.hbase.procedure.Subprocedure.call(Subprocedure.java:181)
  at org.apache.hadoop.hbase.procedure.Subprocedure.call(Subprocedure.java:52)
  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
  at java.util.concurrent.FutureTask.run(FutureTask.java:138)
  at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
  at java.lang.Thread.run(Thread.java:662)
Caused by: org.apache.hadoop.hbase.NotServingRegionException: tableone,,1394495094967.289ebdee6adf0a3b9c2bbcbe2ff522e7. is closing
  at org.apache.hadoop.hbase.regionserver.HRegion.startRegionOperation(HRegion.java:5699)
  at org.apache.hadoop.hbase.regionserver.HRegion.startRegionOperation(HRegion.java:5663)
  at org.apache.hadoop.hbase.regionserver.snapshot.FlushSnapshotSubprocedure$RegionSnapshotTask.call(FlushSnapshotSubprocedure.java:79)
  at org.apache.hadoop.hbase.regionserver.snapshot.FlushSnapshotSubprocedure$RegionSnapshotTask.call(FlushSnapshotSubprocedure.java:65)
  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
  at java.util.concurrent.FutureTask.run(FutureTask.java:138)

Load balancer's move of the underlying region caused FlushSnapshotSubprocedure to fail.

Mechanism of making load balancer be aware of region operation is desirable such that snapshot doesn't fail due to the above scenario.