[FLINK-35065] Add numFiredTimers and numFiredTimersPerSecond metrics

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.19.0
• Fix Version/s: 1.20.0
• Component/s: Runtime / Metrics, Runtime / Task
• Labels: pull-request-available
• Assignee: Piotr Nowojski
• Reporter: Piotr Nowojski
• Created: 09/Apr/24 09:07
• Updated: 08/Jul/24 10:23
• Resolved: 09/Apr/24 15:28

Description

Currently there is no way of knowing how many timers are being fired by Flink, so it's impossible to distinguish, even using code profiling, if operator is firing only a couple of heavy timers per second using ~100% of the CPU time, vs firing thousands of timer per seconds.

We could add the following metrics to address this issue:

• numFiredTimers - total number of fired timers per operator
• numFiredTimersPerSecond - per second rate of firing timers per operator

Issue Links

• is related to: FLINK-32954 Metrics expose number of heap timer
• links to: GitHub Pull Request #24643