[HBASE-15156] Support first assignment of split daughters to non-parent RS

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Abandoned
• Assignee: Unassigned
• Reporter: Francis Christopher Liu
• Created: 21/Jan/16 23:30
• Updated: 23/Jun/22 19:12
• Resolved: 16/Jun/22 17:05

Description

On region split, the region's daughter is always opened by the same region server hosting the parent region. In some cases this is not ideal:

This feature was mainly needed for favored nodes to allow for more freedom when selecting favored nodes for daughter regions. ie The daughter doesn't have to always select the regionserver hosting the split as a favored node which should allow for better favored node distribution.

Though this feature is actually useful in cases where region splits occur much more often than the balancer is run. It also is a bit more efficient as the major compaction that occurs after daughter assignment does not go to waste (ie cancelled half-way, loss of locality due to move, etc). We actually run it this way in some of our clusters even without favored nodes enabled. Hence I am supplying a patch which is independent of favored nodes.

Issue Links

• relates to: HBASE-8549 Integrate Favored Nodes into StochasticLoadBalancer