[HBASE-9734] Save 3-4 seconds by having master purge znode rather than wait on RS exit

• Type: Improvement
• Status: Closed
• Priority: Critical
• Resolution: Incomplete
• Component/s: MTTR
• Assignee: Unassigned
• Reporter: Michael Stack
• Created: 09/Oct/13 17:46
• Updated: 16/Jun/22 18:17
• Resolved: 16/Jun/22 18:17

Description

If RS is aborting (in my current case because SSR and ran out of DM), it will tell the Master its exiting by calling reportRSFatalError on the Master Interface. Master adds the RS to its list of fatal regionservers but that is about it.

RS tries to clean up best as it can and exit out quickly but if carrying regions it can be seconds before it gets to the purge of its ephemeral node, and then the Master needs to notice it and only then can it start in on log splitting.

RS should purge ephemeral node immediately on abort or Master needs to do it and start log splitting as soon as the RS reports fatal error. In my case here would save at least 4 seconds, a small cluster, with only a few regions so there is more to be had in a bigger setup.