[HBASE-16359] NullPointerException in RSRpcServices.openRegion()

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.1.2
• Fix Version/s: 1.4.0, 2.0.0
• Hadoop Flags: Reviewed
• Assignee: Ted Yu
• Reporter: Ted Yu
• Created: 04/Aug/16 22:38
• Updated: 16/Nov/16 06:41
• Resolved: 05/Aug/16 16:16

Description

I was investigating why some region failed to move out of transition within timeout 120000ms and found the following in region server log:

2016-08-04 09:19:52,616 INFO  [B.priority.fifo.QRpcServer.handler=12,queue=0,port=16020] regionserver.RSRpcServices: Open hbck_table_772674,,1470302211047.                                da859880bb51bc0fd25979798a96c444.
2016-08-04 09:19:52,620 ERROR [B.priority.fifo.QRpcServer.handler=12,queue=0,port=16020] ipc.RpcServer: Unexpected throwable object
java.lang.NullPointerException
  at org.apache.hadoop.hbase.regionserver.RSRpcServices.openRegion(RSRpcServices.java:1530)
  at org.apache.hadoop.hbase.protobuf.generated.AdminProtos$AdminService$2.callBlockingMethod(AdminProtos.java:22737)
  at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2127)
  at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:107)
  at org.apache.hadoop.hbase.ipc.RpcExecutor.consumerLoop(RpcExecutor.java:133)

Here is related code - NPE was thrown from the last line:

        htd = htds.get(region.getTable());
        if (htd == null) {
          htd = regionServer.tableDescriptors.get(region.getTable());
          htds.put(region.getTable(), htd);
        }
...
          if (region.isMetaRegion()) {
            regionServer.service.submit(new OpenMetaHandler(
              regionServer, regionServer, region, htd, masterSystemTime, coordination, ord));
          } else {
            regionServer.updateRegionFavoredNodesMapping(region.getEncodedName(),
              regionOpenInfo.getFavoredNodesList());
            if (htd.getPriority() >= HConstants.ADMIN_QOS || region.getTable().isSystemTable()) {

region.getTable() shouldn't be null since it is called via htds.get(region.getTable()) unconditionally.
It seems htd was null.