[KUDU-1049] Add metric for rows_scanned on a tablet

• Type: Improvement
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: Private Beta
• Component/s: metrics
• Target Version/s: Public beta
• Code Review: http://gerrit.sjc.cloudera.com:8080/7596
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 20/Aug/15 19:31
• Updated: 25/Aug/15 21:14
• Resolved: 25/Aug/15 21:14

Description

This is a useful metric to understand read throughput of a cluster, break down by table, etc. If easy, we should also dump in IO stats (bytes read by scanners, even percent of bytes that came from block cache).