[HBASE-6977] Multithread processing ZK assignment events

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.95.0
• Component/s: Region Assignment
• Hadoop Flags: Reviewed
• Assignee: Jimmy Xiang
• Reporter: Jimmy Xiang
• Created: 11/Oct/12 16:58
• Updated: 23/Sep/13 18:31
• Resolved: 25/Oct/12 17:35

Description

Related to HBASE-6976 and HBASE-6611. ZK events processing is a bottle neck for assignments, since there is only one ZK event thread. If we can use multiple threads, it should be better.

With multiple threads, the order of events could be messed up. However, if we pass all events related to one region always to the same worker thread, the order should be kept.

We need to play with it and find out how much performance imrovement we can get.

Issue Links

• depends upon: HBASE-6611 Forcing region state offline cause double assignment
• is related to: HBASE-7022 Use multi to batch offline regions in zookeeper