Version
v14.18.1, v15.14.0, v16.11.1, v17.0.0-pre (as of 16 Oct `21)
Platform
Linux marcus 5.13.19-200.fc34.x86_64 #1 SMP Sat Sep 18 16:32:24 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
Subsystem
worker_threads
What steps will reproduce the bug?
Repository with example: https://github.com/tshemsedinov/wtu
How often does it reproduce? Is there a required condition?
If worker event loop is empty in delta calculation period.
What is the expected behavior?
Delta fields active and utilization are expected to be positive, utilization expected to be [0..1].
What do you see instead?
Negative values in ~50% cases. But if you add setInterval with empty handler for minimum eventloop load, utilization will be always between 0 and 1.
Additional information
I know that it is a stable API but it would be better in far future:
- I'd propose to reduce time between
loopIdleTime() call and now() in lower level, but my experiments in this field is not successful, still getting negative utilization.
- To decompose this function to respect separation of concerns into
performance.eventLoopUsage(): EventLoopUsage and performance.eventLoopUtilization(usage1, usage2): EventLoopUtilization.
- Now we have 6 places to calculate proportion (for utilization), 3 in
internal/worker.js and 3 in internal/perf/event_loop_utilization.js.
Version
v14.18.1, v15.14.0, v16.11.1, v17.0.0-pre (as of 16 Oct `21)
Platform
Linux marcus 5.13.19-200.fc34.x86_64 #1 SMP Sat Sep 18 16:32:24 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
Subsystem
worker_threads
What steps will reproduce the bug?
Repository with example: https://github.com/tshemsedinov/wtu
How often does it reproduce? Is there a required condition?
If worker event loop is empty in delta calculation period.
What is the expected behavior?
Delta fields
activeandutilizationare expected to be positive,utilizationexpected to be[0..1].What do you see instead?
Negative values in ~50% cases. But if you add
setIntervalwith empty handler for minimum eventloop load, utilization will be always between 0 and 1.Additional information
I know that it is a stable API but it would be better in far future:
loopIdleTime()call andnow()in lower level, but my experiments in this field is not successful, still getting negative utilization.performance.eventLoopUsage(): EventLoopUsageandperformance.eventLoopUtilization(usage1, usage2): EventLoopUtilization.internal/worker.jsand 3 ininternal/perf/event_loop_utilization.js.