[HDFS-10782] Decrease memory frequent exchange of Centralized Cache Management when run balancer

• Type: Improvement
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.7.1
• Component/s: balancer & mover, caching
• Labels: patch
• Assignee: Xiaoqiao He
• Reporter: Xiaoqiao He
• Created: 22/Aug/16 04:36
• Updated: 02/Oct/19 17:13

Description

CachedBlocks currently are transparent for Balancer when active feature of centralized cache management. This makes DataNode exchange memory frequently, because Balancer does not Distinguish CachedBlock from blocks, so it may trigger mount of cached/uncached ops.

I think namenode should avoid return CacheBlocks as much as possible when Balanacer#getblocks.