[HBASE-17584] Expose ScanMetrics with ResultScanner rather than Scan

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0
• Fix Version/s: 1.4.0, 2.0.0
• Component/s: Client, mapreduce, Scanners
• Hadoop Flags: Incompatible change, Reviewed

Release Note

Now you can use ResultScanner.getScanMetrics to get the scan metrics at any time during the scan operation. The old Scan.getScanMetrics is deprecated and still work, but if you use ResultScanner.getScanMetrics to get the scan metrics and reset it, then the metrics published to the Scan instaince will be messed up.

• Assignee: Duo Zhang
• Reporter: Duo Zhang
• Created: 02/Feb/17 13:44
• Updated: 07/May/19 16:11
• Resolved: 20/Mar/17 08:36

Description

I think this have been discussed many times... It is a bad practice to directly modify the Scan object passed in when calling getScanner. The reason that we can not use a copy is we need to use the Scan object to expose scan metrics. So we need to find another way to expose the metrics.

Issue Links

• links to: review board