[jira] [Resolved] (HBASE-14129) If any regionserver gets shutdown uncleanly during full cluster restart, locality looks to be lost

["Lars George (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HBASE-14129?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Lars George resolved HBASE-14129.
---------------------------------
    Resolution: Won't Fix

Closing as "won't fix" as the hardcoded flag is too intrusive. The cluster should be able to handle this by fixing the logic in the {{AssignmentManager}}.

> If any regionserver gets shutdown uncleanly during full cluster restart, locality looks to be lost
> --------------------------------------------------------------------------------------------------
>
>                 Key: HBASE-14129
>                 URL: https://issues.apache.org/jira/browse/HBASE-14129
>             Project: HBase
>          Issue Type: Bug
>            Reporter: churro morales
>             Fix For: 2.0.0, 1.4.0
>
>         Attachments: HBASE-14129.patch
>
>
> We were doing a cluster restart the other day.  Some regionservers did not shut down cleanly.  Upon restart our locality went from 99% to 5%.  Upon looking at the AssignmentManager.joinCluster() code it calls AssignmentManager.processDeadServersAndRegionsInTransition().
> If the failover flag gets set for any reason it seems we don't call assignAllUserRegions().  Then it looks like the balancer does the work in assigning those regions, we don't use a locality aware balancer and we lost our region locality.
> I don't have a solid grasp on the reasoning for these checks but there could be some potential workarounds here.
> 1. After shutting down your cluster, move your WALs aside (replay later).  
> 2. Clean up your zNodes 
> That seems to work, but requires a lot of manual labor.  Another solution which I prefer would be to have a flag for ./start-hbase.sh --clean 
> If we start master with that flag then we do a check in AssignmentManager.processDeadServersAndRegionsInTransition()  thus if this flag is set we call: assignAllUserRegions() regardless of the failover state.
> I have a patch for the later solution, that is if I am understanding the logic correctly.



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