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https://issues.apache.org/jira/browse/HBASE-21083?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16704171#comment-16704171
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Allan Yang commented on HBASE-21083:
------------------------------------

[~xucang] this feature is mostly used by HBCK2? how are preparing to use it in 
1.x?

> Introduce a mechanism to bypass the execution of a stuck procedure
> ------------------------------------------------------------------
>
>                 Key: HBASE-21083
>                 URL: https://issues.apache.org/jira/browse/HBASE-21083
>             Project: HBase
>          Issue Type: Sub-task
>          Components: amv2
>    Affects Versions: 2.1.0, 2.0.1
>            Reporter: Allan Yang
>            Assignee: Allan Yang
>            Priority: Major
>             Fix For: 3.0.0, 2.1.1, 2.0.2
>
>         Attachments: HBASE-21083.branch-2.0.001.patch, 
> HBASE-21083.branch-2.0.002.patch, HBASE-21083.branch-2.0.003.patch, 
> HBASE-21083.branch-2.0.003.patch, HBASE-21083.branch-2.0.003.patch, 
> HBASE-21083.branch-2.1.001.patch
>
>
> Offline discussed with [~stack] and [~Apache9]. We all agreed that we need to 
> introduce a mechanism to 'force complete' a stuck procedure, so the AMv2 can 
> continue running.
> we still have some unrevealed bugs hiding in our AMv2 and procedureV2 system, 
> we need something to interfere with stuck procedures before HBCK2 can work. 
> This is very crucial for a production ready system.
> For now, we have little ways to interfere with running procedures. Aborting 
> them is not a good choice, since some procedures are not abort-able. And some 
> procedure may have overridden the abort() method, which will ignore the abort 
> request.
> So, here, I will introduce a mechanism to bypass the execution of a stuck 
> procedure.
> Basically, I added a field called 'bypass' to Procedure class. If we set this 
> field to true, all the logic in execute/rollback will be skipped, letting 
> this procedure and its ancestors complete normally and releasing the lock 
> resources at last.
> Notice that bypassing a procedure may leave the cluster in a middle state, 
> e.g. the region not assigned, or some hdfs files left behind. 
> The Operators need know the side effect of bypassing and recover the 
> inconsistent state of the cluster themselves, like issuing new procedures to 
> assign the regions.
> A patch will be uploaded and review board will be open. For now, only APIs in 
> ProcedureExecutor are provided. If anything is fine, I will add it to master 
> service and add a shell command to bypass a procedure. Or, maybe we can use 
> dynamically compiled JSPs to execute those APIs as mentioned in HBASE-20679.



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