[
https://issues.apache.org/jira/browse/HBASE-24370?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Huaxiang Sun resolved HBASE-24370.
----------------------------------
Fix Version/s: 2.4.0
2.3.0
3.0.0-alpha-1
Resolution: Fixed
> Avoid aggressive MergeRegion and GCMultipleMergedRegionsProcedure
> ------------------------------------------------------------------
>
> Key: HBASE-24370
> URL: https://issues.apache.org/jira/browse/HBASE-24370
> Project: HBase
> Issue Type: Bug
> Components: master
> Reporter: Huaxiang Sun
> Assignee: Huaxiang Sun
> Priority: Major
> Fix For: 3.0.0-alpha-1, 2.3.0, 2.4.0
>
>
> In
> [https://github.com/apache/hbase/blob/a40a0322a73add68d9cb0579abacdd6a2e41e8fb/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MergeTableRegionsProcedure.java#L478,
>
> |https://github.com/apache/hbase/blob/a40a0322a73add68d9cb0579abacdd6a2e41e8fb/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MergeTableRegionsProcedure.java#L478]
> prepareMergeRegion, it checks if one of merged parent regions is a merged
> child region and has not been GCed. If it is ready to GC, it will kick off a
> GCMultipleMergedRegionsProcedure and also start the MergeRegionProcedure.
> There is a race condition here. If MergeRegionProcedure finishes first, it
> will delete meta row for the merged child region. Then
> GCMultipleMergedRegionsProcedure runs, and because the newly added check, it
> thinks GC has been done and wont schedule GCRegionProcedure to clean up those
> merged parent regions. The end result is that these merged parent regions are
> left as orphans on Filesystem.
>
> [https://github.com/apache/hbase/blob/a40a0322a73add68d9cb0579abacdd6a2e41e8fb/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/GCMultipleMergedRegionsProcedure.java#L105]
>
> The proposed solution is to avoid being so aggressive, if it needs to kick
> off GCMultipleMergedRegionsProcedure, then abort MergeRegionProcedure and
> user can try MergeRegionProcedure later.
> [|https://github.com/apache/hbase/blob/a40a0322a73add68d9cb0579abacdd6a2e41e8fb/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MergeTableRegionsProcedure.java#L478]
>
>
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
