[HBASE-13316] Reduce the downtime on planned moves of regions

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.0.1, 1.1.0, 2.0.0
• Fix Version/s: 1.1.0, 2.0.0
• Component/s: Balancer
• Hadoop Flags: Reviewed
• Release Note: When issuing an Admin.move command the RegionServer that receive the region will try and open the StoreFiles of that region to prime the block cache with index blocks.
• Assignee: Sameet Agarwal
• Reporter: Sameet Agarwal
• Created: 23/Mar/15 16:08
• Updated: 03/Jun/15 15:28
• Resolved: 27/Mar/15 19:04

Description

The current behavior of a region move shuts down a region and then starts is up in another regionserver. This causes increased latency and possibly timeouts till the new region's cache is fully warmed up. We can make a region move less disruptive by warming the cache in the destination region server before shutting dow the old region.