[HDFS-13641] Add metrics for edit log tailing

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.3
• Fix Version/s: 3.2.0, 3.1.1, 3.0.4
• Component/s: metrics
• Target Version/s: 3.0.4
• Hadoop Flags: Reviewed
• Assignee: Chao Sun
• Reporter: Chao Sun
• Created: 30/May/18 15:59
• Updated: 13/Jun/18 12:30
• Resolved: 13/Jun/18 12:15

Description

We should add metrics for each iteration of edit log tailing, including 1) # of edits loaded, 2) time spent in select input edit stream, 3) time spent in loading the edits, 4) interval between the iterations.