Massive memory leak when using mobileReplayIntegration

[steelzeh]

What React Native libraries do you use?

Expo (mobile only)

Are you using sentry.io or on-premise?

sentry.io (SaS)

@sentry/react-native SDK Version

6.20.0

How does your development environment look like?

System:
  OS: macOS 14.7.1
  CPU: (10) arm64 Apple M1 Pro
  Memory: 280.23 MB / 16.00 GB
  Shell:
    version: 3.2.57
    path: /bin/sh
Binaries:
  Node:
    version: 22.14.0
    path: /usr/local/bin/node
  Yarn:
    version: 1.22.22
    path: /usr/local/bin/yarn
  npm:
    version: 10.9.2
    path: /usr/local/bin/npm
  Watchman:
    version: 2025.04.14.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods: Not Found
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 24.1
      - iOS 18.1
      - macOS 15.1
      - tvOS 18.1
      - visionOS 2.1
      - watchOS 11.1
  Android SDK: Not Found
IDEs:
  Android Studio: 2024.2 AI-242.23339.11.2421.12700392
  Xcode:
    version: 16.1/16B40
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 21.0.4
    path: /usr/bin/javac
  Ruby:
    version: 2.6.10
    path: /usr/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.0.1
    wanted: latest
  react:
    installed: 19.0.0
    wanted: 19.0.0
  react-native:
    installed: 0.79.6
    wanted: 0.79.6
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: true
  newArchEnabled: true

Sentry.init()

Sentry.init({
  dsn: "**********",

  sendDefaultPii: true,
  replaysSessionSampleRate: 0.1,
  replaysOnErrorSampleRate: 1,
  integrations: [
    Sentry.mobileReplayIntegration({
      maskAllText: false,
      maskAllImages: false,
      maskAllVectors: false,
    }),
  ],

  // uncomment the line below to enable Spotlight (https://spotlightjs.com)
  // spotlight: __DEV__,
});

Steps to Reproduce

1. Run yarn create expo-app
2. Run npx @sentry/wizard@latest -i reactNative
3. Change the Sentry.init function to include mobileReplayIntegration
4. Enable the perf monitor
5. Make a few changes rapidly in the codebase to cause hot-reloads
6. Observe the RAM spike like crazy

Expected Result

No memory spike

Actual Result

Massive memory spike

sentry-memory-leak.mp4

example-project.zip

[linear]

RN-310 Massive memory leak when using mobileReplayIntegration

[kahest]

Hey @steelzeh, to clarify - does this also happen if you run the app normally, or only via triggering hot reloads? Did you compare the memory usage to when replaysSessionSampleRate and replaysOnErrorSampleRate are 0.0?

Also thanks for the sample project, this will help!

[steelzeh]

Hey @steelzeh, to clarify - does this also happen if you run the app normally, or only via triggering hot reloads? Did you compare the memory usage to when replaysSessionSampleRate and replaysOnErrorSampleRate are 0.0?

Also thanks for the sample project, this will help!

Thanks for the quick response @kahest, it does not seem to happen when replaysSessionSampleRate and replaysOnErrorSampleRate are at 0.0

[kahest]

@steelzeh thanks for confirming - can you answer this as well?

does this also happen if you run the app normally, or only via triggering hot reloads