[HBASE-15075] Allow region split request to carry identification information

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Hadoop Flags: Reviewed
• Assignee: Ted Yu
• Reporter: Ted Yu
• Created: 06/Jan/16 22:19
• Updated: 09/Nov/17 02:59
• Resolved: 26/Mar/17 15:53

Description

During the process of improving region normalization feature, I found that if region split request triggered by the execution of SplitNormalizationPlan fails, there is no way of knowing whether the failed split originated from region normalization.

The association of particular split request with outcome of split would give RegionNormalizer information so that it can make better normalization decisions in the subsequent invocations.

One approach is to embed metadata, such as a UUID, in SplitRequest which gets passed through RegionStateTransitionContext when RegionServerServices#reportRegionStateTransition() is called.
This way, RegionStateListener can be notified with the metadata (id of the requester).

See discussion on dev mailing list
http://search-hadoop.com/m/YGbbCXdkivihp2