[sentry-junior]

📜 Description

Removes the traceSampling option for 9.0:

• SentryOptions.isTraceSampling() / setTraceSampling(boolean) and the backing field
• Android manifest key io.sentry.traces.trace-sampling (ManifestMetadataReader.TRACE_SAMPLING)
• The isTraceSampling() gates in SentryTracer and OtelSpanWrapper (traceContext() / toBaggageHeader()), TracingUtils.traceIfAllowed, and SentryApolloInterceptor
• Tests that only covered the option being disabled, plus isTraceSampling = true setup lines that matched the default

After this change:

• traceContext() and toBaggageHeader() return a value whenever the transaction has baggage.
• tracePropagationTargets is the only setting that controls outgoing sentry-trace/baggage headers.

💡 Motivation and Context

traceSampling has defaulted to true since 6.5.0-beta.2 (#2255). The getter is @ApiStatus.Experimental, the setter is @Deprecated in favor of tracePropagationTargets, and both Javadocs say "will be removed without notice". Even so, it still worked as a hidden switch for trace propagation in core, OpenTelemetry, Apollo and Android. Removing it leaves one supported way to control propagation.

Behavior change for anyone who set it to false:

• Outgoing HTTP: they can get the same result with an empty tracePropagationTargets. Apollo is the exception, because it calls TracingUtils.trace directly and has no URL to match against.
• Envelopes: there is no replacement for dropping the envelope trace header. Transactions with baggage always attach it now.

💚 How did you test it?

Ran locally on JDK 21:

• :sentry:test: TracingUtilsTest, SentryTracerTest, SpanTest, SentryClientTest
• :sentry-opentelemetry:sentry-opentelemetry-core:test
• :sentry-openfeign:test
• SentrySpanRest*CustomizerTest in sentry-spring-boot, sentry-spring-boot-jakarta and sentry-spring-boot-4
• :sentry-apollo:compileKotlin
• :sentry:apiDump, plus spotlessApply on the changed JVM modules

No Android SDK was available in the sandbox, so sentry-android-core (ManifestMetadataReader and its test) was not built locally. That change only deletes lines plus the now-unused ApiStatus import. CI should cover it.

📝 Checklist

• I added GH Issue ID & Linear ID
• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.
• Public API changes reviewed by another Mobile SDK team member or implemented according to the develop docs spec.

🔮 Next steps

• Decide whether 9.0 needs a replacement switch for dropping the envelope trace header. I don't think it does, but I'd like a reviewer to confirm.
• Check whether hybrid SDKs (RN, Flutter, Unity, etc.) set traceSampling / io.sentry.traces.trace-sampling.
• Update the docs and the 9.0 migration guide where the option is mentioned.

via alexander.dinauer.

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📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.62.0 (1)	release

⚙️ sentry-android Build Distribution Settings