Adopt Perfetto format for Android 17 profiling #6894

Activity

1. linear-code commented on Oct 15, 2026

   

   linear-codebot

   on Oct 15, 2026 – with Linear Code

   More actions

   RN-828
2. github-actions

   added

   React-Native

   on Oct 15, 2026
3. antonis

   self-assigned this

   on Oct 15, 2026
4. antonis commented on Oct 15, 2026

   

   antonis

   on Oct 15, 2026

   Contributor

   More actions

   Investigated what "adopt Perfetto on Android 17" would involve. Summary: Perfetto is only available for continuous/UI profiling, not for the transaction profiles RN sends today. RN's experimental UI profiling, which would use Perfetto on API 35+, currently doesn't start on RN Android. So adopting Perfetto is a project, not a quick fix, and getsentry/relay#6517 is still needed either way.

   What the code says

   • sentry-android: on API 35+, continuous profiling uses PerfettoContinuousProfiler (Android ProfilingManager). Transaction-based profiling always uses the legacy Debug profiler. AndroidOptionsInitializer.setupProfiler: "Transaction-based profiling always relies on the legacy Debug-based profiler… Perfetto profiling only supports continuous profiling." That matches sentry-java's develop-docs/feature/profiling/perfetto.md: "Only continuous profiling is supported on the Perfetto path — transaction-based and app-start profiling are not."
   • Relay: Perfetto traces are only accepted as profile_chunks (application/x-perfetto-trace, converted to Sample v2). The legacy transaction profile item has no Perfetto path.
   • RN: the default Android profile is a legacy transaction profile (Hermes js_profile plus a Debug method trace). UI profiling exists only as _experiments.profilingOptions, which is forwarded to the native SDKs (RNSentryStart.configureAndroidProfiling). Nothing on the JS side uses it, so no Hermes/JS frames are captured, and Perfetto's native stack sampling wouldn't show JS functions either.

   Tested on Android 17 (API 37 emulator), sample app, with profilingOptions passed natively through sentry.options.json. profilesSampleRate had to be removed natively, since sentry-android turns continuous profiling into a no-op when it's set.

   • Native picks it up: Continuous profiler is enabled true, PerfettoContinuousProfiling integration registered, and Device is API 35+. Skipping legacy app-start profiling — Perfetto ProfilingManager will be initialized after Sentry.init().
   • lifecycle: 'trace': Profiling lifecycle is set to TRACE but tracing is disabled. Profiling will not be started automatically. RN traces in JS, so native tracing is off and the profiler never starts.
   • lifecycle: 'manual' + startOnAppStart: true: no Perfetto/ProfilingManager activity, no chunks captured or sent within about 3 minutes.
   • manual mode has no JS API. The ProfilingOptions.lifecycle JSDoc mentions Sentry.profiler.startProfiler/stopProfiler, but RN doesn't export them.

   What adopting Perfetto would take

   1. Make RN UI profiling actually run on Android: drive the native continuous profiler from JS spans (trace lifecycle doesn't work with JS tracing) and/or expose startProfiler/stopProfiler.
   2. Send Hermes samples as their own profile_chunks linked by profiler_id, so JS frames aren't lost, and confirm with the profiling team that the UI can combine JS and native chunks the way it combines js_profile today.
   3. Account for ProfilingManager's constraints: it's system rate-limited and its results arrive asynchronously. Fine for continuous sessions, not a drop-in for per-transaction start/stop.

   Recommendation

   • Keep Android 17 method traces rejected as profiling_invalid_sampled_profile: new ART header keys unsupported by android_trace_log relay#6517 as the fix for Android 17. It covers all shipped SDK versions and sentry-android's own transaction profiler.
   • Treat Perfetto adoption as part of making RN UI profiling (with Hermes) work end to end on Android, which is also where native Android is heading.
   • Small follow-ups found along the way: the trace lifecycle doesn't work on RN Android, and the JSDoc references a non-existent Sentry.profiler API.
5. christophaigner

   added

   Improvement

   on Oct 16, 2026