[HBASE-2253] Show Block cache hit ratio for requests where cacheBlocks=true

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.90.0
• Hadoop Flags: Reviewed
• Assignee: Jonathan Gray
• Reporter: Dave Latham
• Created: 23/Feb/10 19:48
• Updated: 20/Nov/15 12:40
• Resolved: 30/Oct/10 17:21

Description

We've been disabling block caching for MR jobs and other big scans. It seems to improve cache performance, but it's difficult to measure the hit ratio because even scans that don't cache blocks still request blocks from the cache (which is good), and those requests affect the hit/miss stats, which makes it difficult to see how the queries where cacheBlocks=true are performing.