[HBASE-17716] Formalize Scan Metric names

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.4.0, 1.3.1, 1.2.6, 2.0.0
• Component/s: metrics
• Hadoop Flags: Incompatible change, Reviewed

Release Note

HBASE-17716 breaks compatibility of ServerSideScanMetrics by changing public field names, and the issue is fixed through HBASE-17886

• Assignee: Karan Mehta
• Reporter: Karan Mehta
• Created: 01/Mar/17 23:03
• Updated: 09/Nov/17 19:01
• Resolved: 07/Mar/17 15:45

Description

HBase provides various metrics through the API's exposed by ScanMetrics class.
The JIRA PHOENIX-3248 requires them to be surfaced through the Phoenix Metrics API. Currently these metrics are referred via hard-coded strings, which are not formal and can break the Phoenix API. Hence we need to refactor the code to assign enums for these metrics.