[HBASE-17470] Remove merge region code from region server

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0
• Fix Version/s: 2.0.0
• Component/s: regionserver
• Hadoop Flags: Incompatible change, Reviewed

Release Note

In 1.x branches, Admin.mergeRegions calls MASTER via dispatchMergingRegions RPC; when executing dispatchMergingRegions RPC, MASTER calls RS via MergeRegions to complete the merge in RS-side.

With HBASE-16119, the merge logic moves to master-side. This JIRA cleans up unused RPCs (dispatchMergingRegions and MergeRegions) , removes dangerous tools such as Merge and HMerge, and deletes unused RegionServer-side merge region logic in 2.0 release.

• Assignee: Stephen Yuan Jiang
• Reporter: Stephen Yuan Jiang
• Created: 15/Jan/17 03:17
• Updated: 17/Jun/22 18:06
• Resolved: 18/Jan/17 08:54

Description

HBASE-16119 moves the merge region to the master-side. There is no need to keep region_server-side merge region code to remove logic duplication.

util.Merge and HMerge tools depends on RS-side merge region logic. However, now we can merge regions using shell command. It is dangerous to do offline merge. For 2.0, it is a good time to remove those out-of-date tools.

Issue Links

• depends upon: HBASE-16119 Procedure v2 - Reimplement merge
• is related to: HBASE-17084 Delete HMerge (dead code)
• relates to: HBASE-17761 Test TestRemoveRegionMetrics.testMoveRegion fails intermittently because of race condition