[HBASE-25442] Refactor MultiVersionConcurrencyControl: replace readWaiters.notifyAll() with WriteEntry.notify()

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Won't Fix
• Assignee: Yulin Niu
• Reporter: Yulin Niu
• Created: 24/Dec/20 03:16
• Updated: 15/Jan/21 11:20
• Resolved: 15/Jan/21 11:20

Description

https://github.com/apache/hbase/blob/master/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MultiVersionConcurrencyControl.java#L217 

here the notifyAll() wake up all thread, even the read point no big enough, bring extra thread switch

https://github.com/apache/hbase/blob/master/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MultiVersionConcurrencyControl.java#L143 

WriteEntry object can be thread local to reuse

Issue Links

• links to: GitHub Pull Request #2814