[
https://issues.apache.org/jira/browse/HBASE-21844?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16762461#comment-16762461
]
Duo Zhang commented on HBASE-21844:
-----------------------------------
{quote}
When this happens, the meta state stays OPEN in the ZK, even after master
re-start. I'm currently testing a patch for that. Stay tuned.
{quote}
Could you please explain this more carefully? I mean if HDFS is down, we can
not schedule the SCP for the dead server. And then after master restarts and
the HDFS is back, we will schedule SCP for the dead server again. So what do
you mean by 'even after master re-start'?
Of course, for your case, if the location of meta region is on a dead server
and there is no SCP for the dead server, then no matter how many times you
restart master it will keep in that state... But here we need to find out how
did meta go into the state.
> Master could get stuck in initializing state while waiting for meta
> -------------------------------------------------------------------
>
> Key: HBASE-21844
> URL: https://issues.apache.org/jira/browse/HBASE-21844
> Project: HBase
> Issue Type: Bug
> Components: master, meta
> Affects Versions: 3.0.0
> Reporter: Bahram Chehrazy
> Assignee: Bahram Chehrazy
> Priority: Major
> Attachments:
> 0001-HBASE-21844-Handling-incorrect-Meta-state-on-Zookeep.patch
>
>
> If the active master crashes after meta server dies, there is a slight chance
> of master getting into a state where the ZK says meta is OPEN, but the server
> is dead and there is no active SCP to recover it (perhaps the SCP has aborted
> and the procWALs were corrupted). In this case the waitForMetaOnline never
> returns.
>
> We've seen this happening a few times when there had been a temporary HDFS
> outage. Following log lines shows this state.
>
> 2019-01-17 18:55:48,497 WARN [master/************:16000:becomeActiveMaster]
> master.HMaster: hbase:meta,,1.1588230740 is NOT online; state=
> {1588230740 *state=*OPEN**, ts=1547780128227,
> server=*************,16020,1547776821322}
> ; *ServerCrashProcedures=false*. Master startup cannot progress, in
> holding-pattern until region onlined.
>
> I'm still investigating why and how to prevent getting into this bad state,
> but nevertheless the master should be able to recover during a restart by
> initiating a new SCP to fix the meta.
>
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
