Stabilize SpanProcessor#onEnding

[jack-berg]

Tracking issue to stabilize SpanProcessor#onEnding

This was added >2 years ago in April 2024: #4024

Java has prototyped this here: https://github.com/open-telemetry/opentelemetry-java/blob/1ec8bce84b378508c802788215afb0a6c67cfbff/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/internal/ExtendedSpanProcessor.java#L33

What's the status of other languages?

[dyladan]

JS implemented 7 months ago with @experimental notation in JSDoc string https://github.com/open-telemetry/opentelemetry-js/blob/ffe4f5dbe741a40ba2596875fc78c43df390f7dd/packages/opentelemetry-sdk-trace-base/src/SpanProcessor.ts#L34

Not used in any of our official SpanProcessors except the MultiSpanProcessor which calls all of its children SpanProcessor#onEnding https://github.com/open-telemetry/opentelemetry-js/blob/ffe4f5dbe741a40ba2596875fc78c43df390f7dd/packages/opentelemetry-sdk-trace-base/src/MultiSpanProcessor.ts#L48

[martincostello]

For .NET there was an unmerged attempt here: open-telemetry/opentelemetry-dotnet#6617

[xrmx]

We have this in Python since end of last year using as a private method _on_ending in open-telemetry/opentelemetry-python#4775. This is called at span end and is implemented only in SynchronousMultiSpanProcessor and ConcurrentMultiSpanProcessor processors.

[Nevay]

Added in PHP as experimental ExtendedSpanProcessorInterface::onEnding(ReadWriteSpanInterface) in open-telemetry/opentelemetry-php#1483 / open-telemetry/opentelemetry-php#1785

[pellared]

For OTel Go there was an unmerged and not approved attempt here: open-telemetry/opentelemetry-go#5756. There were not resolved issues related to concurrency-safety.

[arielvalentin]

For OTel Go there was an unmerged and not approved attempt here: open-telemetry/opentelemetry-go#5756. There were not resolved issues related to concurrency-safety.

Same for Ruby. open-telemetry/opentelemetry-ruby#1740