[HBASE-9044] Merging regions throws NPE

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.98.0, 0.95.2
• Hadoop Flags: Reviewed
• Assignee: Jimmy Xiang
• Reporter: Jimmy Xiang
• Created: 25/Jul/13 20:55
• Updated: 23/Sep/13 19:22
• Resolved: 26/Jul/13 22:54

Description

hbase(main):003:0> merge_region '92ade79eb3ac390b09e2b19c74b56dad', '92ade79eb3ac390b09e2b19c74b56dad'
2013-07-25 13:21:23,991 ERROR [main] client.HBaseAdmin: Unexpected exception: com.google.protobuf.ServiceException: org.apache.hadoop.hbase.ipc.RemoteWithExtrasException(java.lang.NullPointerException): java.lang.NullPointerException
	at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2108)
	at org.apache.hadoop.hbase.ipc.RpcServer$CallRunner.run(RpcServer.java:1809)
	at org.apache.hadoop.hbase.ipc.SimpleRpcScheduler.consumerLoop(SimpleRpcScheduler.java:165)
	at org.apache.hadoop.hbase.ipc.SimpleRpcScheduler.access$000(SimpleRpcScheduler.java:41)
	at org.apache.hadoop.hbase.ipc.SimpleRpcScheduler$1.run(SimpleRpcScheduler.java:113)
	at java.lang.Thread.run(Thread.java:662)
 from calling HMaster.dispatchMergingRegions
0 row(s) in 0.0160 seconds

I also saw the following in the master log:

2013-07-25 13:25:12,683 ERROR [MASTER_TABLE_OPERATIONS-a1220:36000-0] executor.EventHandler: Caught throwable while processing event C_M_MERGE_REGION
java.lang.NullPointerException
        at org.apache.hadoop.hbase.master.handler.DispatchMergingRegionHandler.process(DispatchMergingRegionHandler.java:104)
        at org.apache.hadoop.hbase.executor.EventHandler.run(EventHandler.java:130)
        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)