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https://issues.apache.org/jira/browse/HBASE-21627?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16727766#comment-16727766
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Duo Zhang commented on HBASE-21627:
-----------------------------------
Agree that we do not need to wait for non default meta replicas to be online
when starting HMaster.
But I'm afraid that the old code just wants to confirm that the meta replicas
can work. I can see lots of comments in the code base which are always
something like "TODO: handle meta replicas". So here I think we'd better find
out a complete solution for meta replicas, i.e, how to initialize meta replicas
for a fresh new cluster, how to increase or decrease meta replicas, and how
deal with meta replicas in SCP and TRSP.
> race condition between a recovered RIT for meta replica, and master startup
> ---------------------------------------------------------------------------
>
> Key: HBASE-21627
> URL: https://issues.apache.org/jira/browse/HBASE-21627
> Project: HBase
> Issue Type: Bug
> Reporter: Sergey Shelukhin
> Priority: Major
>
> Master recovers RIT for a meta replica
> {noformat}
> 2018-12-14 23:16:12,008 INFO [master/...:17000:becomeActiveMaster]
> assignment.AssignmentManager: Attach pid=83796, ppid=83788,
> state=RUNNABLE:REGION_STATE_TRANSITION_OPEN, hasLock=false;
> TransitRegionStateProcedure table=hbase:meta, region=(region), ASSIGN to
> rit=OFFLINE, location=null, table=hbase:meta, region=(region) to restore RIT
> 2018-12-14 23:16:16,475 WARN [PEWorker-8]
> assignment.TransitRegionStateProcedure: No location specified for {ENCODED =>
> (region), NAME => 'hbase:meta,,1_0001', STARTKEY => '', ENDKEY => '',
> REPLICA_ID => 1}, jump back to state
> REGION_STATE_TRANSITION_GET_ASSIGN_CANDIDATE to get one
> ...
> 2018-12-14 23:16:30,010 INFO [PEWorker-16] procedure2.ProcedureExecutor:
> Finished pid=83796, ppid=83788, state=SUCCESS, hasLock=false;
> TransitRegionStateProcedure table=hbase:meta, region=(region), ASSIGN in
> 8mins, 23.39sec
> {noformat}
> Then tries to assign replicas..
> {noformat}
> 2018-12-14 23:16:36,091 ERROR [master/...:17000:becomeActiveMaster]
> master.HMaster: Failed to become active master
> org.apache.hadoop.hbase.client.DoNotRetryRegionException: Unexpected state
> for rit=OPEN, location=server,17020,1544858156805, table=hbase:meta,
> region=(region)
> at
> org.apache.hadoop.hbase.master.assignment.AssignmentManager.preTransitCheck(AssignmentManager.java:548)
> at
> org.apache.hadoop.hbase.master.assignment.AssignmentManager.assign(AssignmentManager.java:563)
> at
> org.apache.hadoop.hbase.master.MasterMetaBootstrap.assignMetaReplicas(MasterMetaBootstrap.java:84)
> at
> org.apache.hadoop.hbase.master.HMaster.finishActiveMasterInitialization(HMaster.java:1146)
> {noformat}
> Unfortunately I misplaced the log from this after copy-pasting a grep result
> so that's all I have for this.
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