Major Description
I think it is easy to find out the problem. We haven't done a compaction after merging and then try to split the region. The split will fail because of there are still reference files.
2018-04-08 05:29:49,742 INFO [RpcServer.default.FPBQ.Fifo.handler=4,queue=0,port=43056] master.HMaster$2(1644): Client=jenkins//67.195.81.155 split TestNamespaceAuditor_regiontest:table2,,1523165387443.c6dd29ca77051607ab50a1edfa5f076f. 2018-04-08 05:29:49,745 DEBUG [RpcServer.priority.FPBQ.Fifo.handler=1,queue=0,port=38141] regionserver.HRegion(1360): Region TestNamespaceAuditor_regiontest:table2,,1523165387443.c6dd29ca77051607ab50a1edfa5f076f. is not mergeable because it has references 2018-04-08 05:29:49,746 DEBUG [RpcServer.default.FPBQ.Fifo.handler=4,queue=0,port=43056] assignment.SplitTableRegionProcedure(174): Splittable=false rit=OPEN, location=asf911.gq1.ygridcore.net,38141,1523165245520 2018-04-08 05:29:49,747 DEBUG [RpcServer.default.FPBQ.Fifo.handler=4,queue=0,port=43056] ipc.CallRunner(142): callId: 1092 service: MasterService methodName: SplitRegion size: 113 connection: 67.195.81.155:58584 deadline: 1523165449742, exception=org.apache.hadoop.hbase.DoNotRetryIOException: c6dd29ca77051607ab50a1edfa5f076f NOT splittable 2018-04-08 05:29:49,752 INFO [Time-limited test] client.HBaseAdmin$15(907): Started disable of TestNames