Add JFR metrics for virtual thread pinning and submit failures#19092
Add JFR metrics for virtual thread pinning and submit failures#19092tsawada wants to merge 2 commits into
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Pull request overview
This PR adds two new JFR-based runtime-telemetry metrics for virtual threads: jvm.thread.virtual.pinned (a histogram of pinning durations from jdk.VirtualThreadPinned) and jvm.thread.virtual.submit_failed (a counter from jdk.VirtualThreadSubmitFailed). Both are gated behind a new experimental, default-disabled VIRTUAL_THREAD_METRICS JfrFeature. The handlers live in the existing java17 source set (the events exist since Java 19), and a new testJava21 source set is introduced to host tests that need GA virtual-thread APIs. The new handlers closely mirror the existing LongLockHandler pattern and are wired into HandlerRegistry.
Changes:
- Add
VirtualThreadPinnedHandlerandVirtualThreadSubmitFailedHandler, plus theVIRTUAL_THREAD_METRICSfeature, and register both handlers. - Add a
testJava21source set, configurations, compile/test task wiring, and aJfrVirtualThreadPinnedTest.
Reviewed changes
Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.
Show a summary per file
| File | Description |
|---|---|
.../internal/threads/VirtualThreadPinnedHandler.java |
New handler recording pinning duration as a seconds histogram. |
.../internal/threads/VirtualThreadSubmitFailedHandler.java |
New handler counting submit-failed events. |
.../internal/JfrFeature.java |
Adds the experimental, default-disabled VIRTUAL_THREAD_METRICS feature. |
.../internal/HandlerRegistry.java |
Registers the two new handlers. |
.../build.gradle.kts |
Adds testJava21 source set, configurations, compile/test tasks, and check wiring. |
.../testJava21/.../JfrVirtualThreadPinnedTest.java |
New Java 21+ test exercising virtual-thread pinning. |
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| int feature = Runtime.version().feature(); | ||
| Assumptions.assumeTrue(feature >= 21 && feature < 24, "Requires Java 21-23"); |
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could consider @EnabledOnJre(JRE.JAVA_21)
laurit
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https://github.com/open-telemetry/opentelemetry-java-instrumentation/blob/main/instrumentation/runtime-telemetry/library/README.md should be updated with the added metrics
jdk.VirtualThreadPinnedasjvm.thread.virtual.pinnedhistogram (seconds)jdk.VirtualThreadSubmitFailedasjvm.thread.virtual.submit_failedcounterVIRTUAL_THREAD_METRICSfeature to JfrFeature (experimental, disabled by default) - Add testJava21 source set for tests requiring Java 21+ APIsBoth events exist since Java 19. The implementation lives in the java17 source set since only the event name strings depend on JVM version.
No test for
VirtualThreadSubmitFailed, as I couldn't come up with a reliable way to trigger it.VirtualThreadPinnedthreshold defaults to 20 ms, which may be worth making configurable. Other handlers such as LongLockHandler also rely on the JFR default threshold, so I've kept the same approach here.Related: #14949