[HBASE-24367] ScheduledChore log elapsed timespan in a human-friendly format

• Type: Task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.3.0
• Fix Version/s: 3.0.0-alpha-1, 2.3.0, 2.2.6
• Component/s: master, regionserver
• Assignee: Andrew Kyle Purtell
• Reporter: Nick Dimiduk
• Created: 13/May/20 22:30
• Updated: 10/Jun/20 14:26
• Resolved: 09/Jun/20 16:56

Description

I noticed this in a log line,

2020-04-23 18:31:14,183 INFO org.apache.hadoop.hbase.ScheduledChore: host-a.example.com,16000,1587577999888-ClusterStatusChore average execution time: 68488258 ns.

I'm not sure if there's a case when elapsed time in nanoseconds is meaningful for these background chores, but we could do a little work before printing the number and time unit to truncate precision down to something a little more intuitive for operators. This number purports to be an average, so a high level of precision isn't necessarily meaningful.

Separately, or while we're here, if we think an operator really cares about the performance of this chore, we should print a histogram of elapsed times, rather than an opaque average.

Issue Links

• links to: GitHub Pull Request #1749