[IMPALA-4764] add hedged read metrics

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 2.8.0
• Fix Version/s: Impala 2.9.0
• Component/s: Backend
• Target Version: Impala 2.10.0
• Assignee: Sailesh Mukil
• Reporter: Silvius Rus
• Created: 13/Jan/17 05:58
• Updated: 18/May/17 01:07
• Resolved: 18/May/17 01:07

Description

Expose the following Hadoop metrics:
hedgedReadOps - the number of hedged reads that have occurred
hedgeReadOpsWin - the number of times the hedged read returned faster than the original read

Issue Links

• relates to: IMPALA-4917 add tests and measure limits/recommendations for hedged reads