[HBASE-26731] Metrics for tracking of active scanners

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.5.0, 3.0.0-alpha-3
• Labels: patch-available
• Hadoop Flags: Reviewed
• Assignee: Bryan Beaudreault
• Reporter: Bryan Beaudreault
• Created: 04/Feb/22 13:07
• Updated: 01/Sep/22 10:57
• Resolved: 04/Mar/22 22:15

Description

Active scanners take up resources on the RegionServer. This can result in GC issues or even OOMs in cases of leaked scanners. It'd be helpful to have metrics for tracking scanners. I was thinking of:

• activeScanners - a gauge, showing the number of active scanners at a point in time
• scannerLeaseExpirations - a counter of lease expirations

Issue Links

• links to: GitHub Pull Request #4145