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https://issues.apache.org/jira/browse/HBASE-6438?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13432008#comment-13432008
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ramkrishna.s.vasudevan commented on HBASE-6438:
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This patch solves the problem of depending on TM in case of RIT exception. Pls 
provide your suggestions.
 
                
> RegionAlreadyInTransitionException needs to give more info to avoid 
> assignment inconsistencies
> ----------------------------------------------------------------------------------------------
>
>                 Key: HBASE-6438
>                 URL: https://issues.apache.org/jira/browse/HBASE-6438
>             Project: HBase
>          Issue Type: Bug
>            Reporter: ramkrishna.s.vasudevan
>            Assignee: rajeshbabu
>         Attachments: HBASE-6438_trunk.patch
>
>
> Seeing some of the recent issues in region assignment, 
> RegionAlreadyInTransitionException is one reason after which the region 
> assignment may or may not happen(in the sense we need to wait for the TM to 
> assign).
> In HBASE-6317 we got one problem due to RegionAlreadyInTransitionException on 
> master restart.
> Consider the following case, due to some reason like master restart or 
> external assign call, we try to assign a region that is already getting 
> opened in a RS.
> Now the next call to assign has already changed the state of the znode and so 
> the current assign that is going on the RS is affected and it fails.  The 
> second assignment that started also fails getting RAITE exception.  Finally 
> both assignments not carrying on.  Idea is to find whether any such RAITE 
> exception can be retried or not.
> Here again we have following cases like where
> -> The znode is yet to transitioned from OFFLINE to OPENING in RS
> -> RS may be in the step of openRegion.
> -> RS may be trying to transition OPENING to OPENED.
> -> RS is yet to add to online regions in the RS side.
> Here in openRegion() and updateMeta() any failures we are moving the znode to 
> FAILED_OPEN.  So in these cases getting an RAITE should be ok.  But in other 
> cases the assignment is stopped.
> The idea is to just add the current state of the region assignment in the RIT 
> map in the RS side and using that info we can determine whether the 
> assignment can be retried or not on getting an RAITE.
> Considering the current work going on in AM, pls do share if this is needed 
> atleast in the 0.92/0.94 versions?  

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