[
https://issues.apache.org/jira/browse/HBASE-20921?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16553311#comment-16553311
]
stack commented on HBASE-20921:
-------------------------------
LGTM
> Possible NPE in ReopenTableRegionsProcedure
> -------------------------------------------
>
> Key: HBASE-20921
> URL: https://issues.apache.org/jira/browse/HBASE-20921
> Project: HBase
> Issue Type: Sub-task
> Components: amv2
> Affects Versions: 3.0.0, 2.1.0, 2.0.2
> Reporter: Allan Yang
> Assignee: Allan Yang
> Priority: Major
> Attachments: HBASE-20921.branch-2.0.001.patch
>
>
> After HBASE-20752， we issue a ReopenTableRegionsProcedure in
> ModifyTableProcedure to ensure all regions are reopened.
> But, ModifyTableProcedure and ReopenTableRegionsProcedure do not hold the
> lock (why?), so there is a chance that while ModifyTableProcedure executing,
> a merge/split procedure can be executed at the same time.
> So, when ReopenTableRegionsProcedure reaches the state of
> "REOPEN_TABLE_REGIONS_CONFIRM_REOPENED", some of the persisted regions to
> check is actually not exists, thus a NPE will throw.
> {code}
> 2018-07-18 01:38:57,528 INFO [PEWorker-9]
> procedure2.ProcedureExecutor(1246): Finished pid=6110, state=SUCCESS;
> MergeTableRegionsProcedure table=IntegrationTestBigLinkedList,
> regions=[845d286231eb01b7
> 1aeaa17b0e30058d, 4a46ab0918c99cada72d5336ad83a828], forcibly=false in
> 10.8610sec
> 2018-07-18 01:38:57,530 ERROR [PEWorker-8]
> procedure2.ProcedureExecutor(1478): CODE-BUG: Uncaught runtime exception:
> pid=5974, ppid=5973, state=RUNNABLE:REOPEN_TABLE_REGIONS_CONFIRM_REOPENED;
> ReopenTab
> leRegionsProcedure table=IntegrationTestBigLinkedList
> java.lang.NullPointerException
> at
> org.apache.hadoop.hbase.master.assignment.RegionStates.checkReopened(RegionStates.java:651)
> at
> java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
> at
> java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382)
> at
> java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
> at
> java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
> at
> java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
> at
> java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
> at
> java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
> at
> org.apache.hadoop.hbase.master.procedure.ReopenTableRegionsProcedure.executeFromState(ReopenTableRegionsProcedure.java:102)
> at
> org.apache.hadoop.hbase.master.procedure.ReopenTableRegionsProcedure.executeFromState(ReopenTableRegionsProcedure.java:45)
> at
> org.apache.hadoop.hbase.procedure2.StateMachineProcedure.execute(StateMachineProcedure.java:184)
> at
> org.apache.hadoop.hbase.procedure2.Procedure.doExecute(Procedure.java:850)
> at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor.execProcedure(ProcedureExecutor.java:1453)
> at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor.executeProcedure(ProcedureExecutor.java:1221)
> at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor.access$800(ProcedureExecutor.java:75)
> at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor$WorkerThread.run(ProcedureExecutor.java:1741)
> {code}
> I think we need to renew the region list of the table at the
> "REOPEN_TABLE_REGIONS_CONFIRM_REOPENED" state. For the regions which are
> merged or split, we do not need to check it. Since we can be sure that they
> are opened after we made change to table descriptor.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
