Deprecate runtime telemetry individual metric classes by trask · Pull Request #16064 · open-telemetry/opentelemetry-java-instrumentation

trask · 2026-01-29T20:45:13Z

Towards

Stabilize runtime telemetry library modules #16063

I think metric view are good enough to include/exclude individual metrics as needed, so can remove these from public API.

cc @roberttoyonaga

SylvainJuge · 2026-01-30T08:39:11Z

-    observables.addAll(MemoryPools.registerObservers(openTelemetry));
-    observables.addAll(Threads.registerObservers(openTelemetry));
+    observables.addAll(
+        io.opentelemetry.instrumentation.runtimemetrics.java8.Classes.registerObservers(


Is there a good reason to use FQN here ?

this is usually done so because importing deprecated classes causes warnings that can't be suppressed and the build is configured to fail on warnings

yeah, it's annoying...

SylvainJuge · 2026-01-30T08:41:50Z

+    observables.addAll(
+        io.opentelemetry.instrumentation.runtimemetrics.java8.Threads.registerObservers(
+            openTelemetry));
    if (emitExperimentalTelemetry) {


If we suggest using metric views to filter experimental metrics, does this means we would also get rid of this condition or do we still keep it ? From what I understand here the goal for now is only to make the individual metric classes internal.

I think we keep it, at least for now. We could consider removing it after open-telemetry/opentelemetry-specification#4809, though we could also keep it even then as "emit experimental telemetry" is a pattern we use throughout.

SylvainJuge · 2026-01-30T08:43:54Z

+runtimeMetrics.close();
 ```

+To select specific metrics, configure [metric views](https://opentelemetry.io/docs/specs/otel/metrics/sdk/#view)


Do we have an example implementation with Java SDK we could link to ?

laurit · 2026-01-30T10:56:10Z

+ * @deprecated Use {@link io.opentelemetry.instrumentation.runtimemetrics.java8.RuntimeMetrics}
+ *     instead, and configure metric views to select specific metrics.
 */
+@Deprecated


since this is an internal class we don't really need to do anything with it

I tend to think of .internal.Experimental* as one step above other .internal classes. since easy in this case (and doesn't require annoying copy), I'd suggest go ahead with deprecation (but agree we don't necessarily need to)

laurit · 2026-01-30T10:59:22Z

+ * @deprecated Use {@link RuntimeMetrics} instead, and configure metric views to select specific
+ *     metrics.
 */
+@Deprecated


if your goal is just to move these to internal then maybe it would be easier to move the class, drop final, add deprecated class in original location that extends the moved class

done in cfbec4d

Copilot

Pull request overview

This pull request deprecates individual runtime telemetry metric classes in favor of using the RuntimeMetrics API with metric views to control which metrics are emitted. This change simplifies the public API by moving implementation classes to an internal package while maintaining backward compatibility through deprecated wrapper classes.

Changes:

Moved implementation classes (Classes, Cpu, GarbageCollector, MemoryPools, Threads) from public API to internal package
Deprecated public API classes with delegation to internal implementations
Marked experimental metric classes (ExperimentalBufferPools, ExperimentalCpu, ExperimentalMemoryPools, ExperimentalFileDescriptor) as deprecated
Updated README with comprehensive examples showing how to use RuntimeMetrics with metric views for selective metric collection

Reviewed changes

Copilot reviewed 25 out of 25 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
`Classes.java` (public API)	Converted to deprecated wrapper that delegates to internal implementation
`Cpu.java` (public API)	Converted to deprecated wrapper that delegates to internal implementation
`GarbageCollector.java` (public API)	Converted to deprecated wrapper that delegates to internal implementation
`MemoryPools.java` (public API)	Converted to deprecated wrapper that delegates to internal implementation
`Threads.java` (public API)	Converted to deprecated wrapper that delegates to internal implementation
`Classes.java` (internal)	New internal implementation class moved from public package
`Cpu.java` (internal)	New internal implementation class moved from public package
`GarbageCollector.java` (internal)	New internal implementation class moved from public package
`MemoryPools.java` (internal)	New internal implementation class moved from public package
`Threads.java` (internal)	New internal implementation class moved from public package
`ExperimentalBufferPools.java`	Added @deprecated annotation with guidance to use RuntimeMetrics
`ExperimentalCpu.java`	Added @deprecated annotation with guidance to use RuntimeMetrics
`ExperimentalMemoryPools.java`	Added @deprecated annotation with guidance to use RuntimeMetrics
`ExperimentalFileDescriptor.java`	Added @deprecated annotation with guidance to use RuntimeMetrics
`JmxRuntimeMetricsFactory.java`	Updated to reference internal classes directly, added deprecation suppression
`ClassesTest.java`	Moved to internal package with updated imports
`CpuTest.java`	Moved to internal package with updated imports
`GarbageCollectorTest.java`	Moved to internal package with updated imports
`MemoryPoolsTest.java`	Moved to internal package with updated imports
`ThreadsTest.java`	Moved to internal package with updated imports
`ExperimentalBufferPoolsTest.java`	Added deprecation suppression annotation
`ExperimentalCpuTest.java`	Added deprecation suppression annotation
`ExperimentalMemoryPoolsTest.java`	Added deprecation suppression annotation
`ExperimentalFileDescriptorTest.java`	Added deprecation suppression annotation
`README.md`	Updated with new usage examples showing RuntimeMetrics API and metric view configuration

trask force-pushed the runtime-telemetry branch from 39023c9 to 9a8a9bb Compare January 29, 2026 21:00

Deprecate runtime telemetry individual metric classes

b4d9d99

trask force-pushed the runtime-telemetry branch from 9a8a9bb to b4d9d99 Compare January 29, 2026 21:53

trask mentioned this pull request Jan 29, 2026

Stabilize runtime telemetry library modules #16063

Open

4 tasks

trask marked this pull request as ready for review January 29, 2026 22:57

trask requested a review from a team as a code owner January 29, 2026 22:57

SylvainJuge reviewed Jan 30, 2026

View reviewed changes

laurit reviewed Jan 30, 2026

View reviewed changes

trask added 2 commits January 30, 2026 08:42

move

cfbec4d

Better docs

bf2412f

trask requested a review from Copilot January 30, 2026 17:41

Copilot started reviewing on behalf of trask January 30, 2026 17:44 View session

Copilot AI reviewed Jan 30, 2026

View reviewed changes

roberttoyonaga approved these changes Jan 30, 2026

View reviewed changes

laurit approved these changes Jan 30, 2026

View reviewed changes

trask merged commit 0ef71c8 into open-telemetry:main Jan 30, 2026
90 of 91 checks passed

trask deleted the runtime-telemetry branch January 30, 2026 18:21

trask mentioned this pull request Feb 3, 2026

Unify runtime-telemetry modules #16087

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Deprecate runtime telemetry individual metric classes#16064

Deprecate runtime telemetry individual metric classes#16064
trask merged 3 commits intoopen-telemetry:mainfrom
trask:runtime-telemetry

trask commented Jan 29, 2026 •

edited

Loading

Uh oh!

SylvainJuge Jan 30, 2026

Uh oh!

laurit Jan 30, 2026

Uh oh!

trask Jan 30, 2026

Uh oh!

SylvainJuge Jan 30, 2026

Uh oh!

trask Jan 30, 2026

Uh oh!

SylvainJuge Jan 30, 2026

Uh oh!

trask Jan 30, 2026

Uh oh!

laurit Jan 30, 2026

Uh oh!

trask Jan 30, 2026

Uh oh!

laurit Jan 30, 2026

Uh oh!

trask Jan 30, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

Conversation

trask commented Jan 29, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

trask commented Jan 29, 2026 •

edited

Loading