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https://issues.apache.org/jira/browse/HBASE-21035?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16979442#comment-16979442
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Michael Stack commented on HBASE-21035:
---------------------------------------

To address more directly [~allan163]'s original description:

 "Since no one will bring meta region online."

We added 'fix' to hbck2 to address above.

'hbck2 --skip assigns 1588230740' will force assign of hbase:meta if Master 
stuck in startup waiting on hbase:meta to online AND no Procedure to assign 
hbase:meta (because for example, MasterProcWALs have all been removed.... or 
are corrupt). See the help usage from hbck2 for the assigns command. Will also 
work for namespace region assign (HBASE-21156).



{quote} assigns [OPTIONS] <ENCODED_REGIONNAME>...
   Options:
    -o,--override  override ownership by another procedure
   A 'raw' assign that can be used even during Master initialization (if
   the -skip flag is specified). Skirts Coprocessors. Pass one or more
   encoded region names. 1588230740 is the hard-coded name for the
   hbase:meta region and de00010733901a05f5a2a3a382e27dd4 is an example of
   what a user-space encoded region name looks like. For example:
     $ HBCK2 assign 1588230740 de00010733901a05f5a2a3a382e27dd4
   Returns the pid(s) of the created AssignProcedure(s) or -1 if none.{quote}

> Meta Table should be able to online even if all procedures are lost
> -------------------------------------------------------------------
>
>                 Key: HBASE-21035
>                 URL: https://issues.apache.org/jira/browse/HBASE-21035
>             Project: HBase
>          Issue Type: Sub-task
>    Affects Versions: 2.1.0
>            Reporter: Allan Yang
>            Assignee: Allan Yang
>            Priority: Major
>         Attachments: HBASE-21035.branch-2.0.001.patch, 
> HBASE-21035.branch-2.1.001.patch
>
>
> After HBASE-20708, we changed the way we init after master starts. It will 
> only check WAL dirs and compare to Zookeeper RS nodes to decide which server 
> need to expire. For servers which's dir is ending with 'SPLITTING', we assure 
> that there will be a SCP for it.
> But, if the server with the meta region crashed before master restarts, and 
> if all the procedure wals are lost (due to bug, or deleted manually, 
> whatever), the new restarted master will be stuck when initing. Since no one 
> will bring meta region online.
> Although it is an anomaly case, but I think no matter what happens, we need 
> to online meta region. Otherwise, we are sitting ducks, noting can be done.



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