[HBASE-4349] Add metrics for monitored tasks and executor services

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 0.92.0
• Component/s: metrics
• Labels: beginner
• Assignee: Unassigned
• Reporter: Todd Lipcon
• Created: 07/Sep/11 22:42
• Updated: 12/Jun/22 19:11
• Resolved: 12/Jun/22 19:11

Description

Would be nice to add some metrics for each of the monitored tasks and executor services in the master and region server:

• number of items in the queue
• age of the oldest yet-unprocessed item (ie in the queue or currently being handled)
• number of threads in the executor currently busy

These would allow us to monitor better for cases where things get "stuck"