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https://issues.apache.org/jira/browse/HBASE-15251?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15924349#comment-15924349
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Lars George commented on HBASE-15251:
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I believe this is not enough, as a failed server should be handled better, no
matter if it had regions or not. Also, this should be ported to all 1.x
branches.
> During a cluster restart, Hmaster thinks it is a failover by mistake
> --------------------------------------------------------------------
>
> Key: HBASE-15251
> URL: https://issues.apache.org/jira/browse/HBASE-15251
> Project: HBase
> Issue Type: Bug
> Components: master
> Affects Versions: 2.0.0
> Reporter: Clara Xiong
> Assignee: Clara Xiong
> Fix For: 2.0.0
>
> Attachments: HBASE-15251-master.patch, HBASE-15251-master-v1.patch
>
>
> We often need to do cluster restart as part of release for a cluster of >
> 1000 nodes. We have tried our best to get clean shutdown but 50% of the time,
> hmaster still thinks it is a failover. This increases the restart time from 5
> min to 30 min and decreases locality from 99% to 5% since we didn't use a
> locality-aware balancer. We had a bug HBASE-14129 but the fix didn't work.
> After adding more logging and inspecting the logs, we identified two things
> that trigger the failover handling:
> 1. When Hmaster.AssignmentManager detects any dead servers on service
> manager during joinCluster(), it determines this is a failover without
> further check. I added a check whether there is even any region assigned to
> these servers. During a clean restart, the regions are not even assigned.
> 2. When there are some leftover empty folders for log and split directories
> or empty wal files, it is also treated as a failover. I added a check for
> that. Although this can be resolved by manual cleanup, it is still too
> tedious for restarting a large cluster.
> Patch will follow shortly. The fix is tested and used in production now.
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