App hanging for at least 2000 ms: NewRelic::EventManager::addEvent

[G2Jose]

Description

I'm noticing several "App Hang" events picked up by sentry that are pointing to NewRelic::EventManager::addEvent being the root cause. It seems to happen sporadically.

Here's a stack trace I see:

Your Environment

System:
  OS: macOS 15.5
  CPU: (12) arm64 Apple M2 Pro
  Memory: 574.70 MB / 32.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 24.3.0
    path: ~/.local/share/mise/installs/node/24.3.0/bin/node
  Yarn:
    version: 4.4.1
    path: /opt/homebrew/bin/yarn
  npm:
    version: 11.4.2
    path: ~/.local/share/mise/installs/node/24.3.0/bin/npm
  Watchman:
    version: 2025.07.21.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: /Users/georgejose/.rbenv/shims/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 24.5
      - iOS 18.5
      - macOS 15.5
      - tvOS 18.5
      - visionOS 2.5
      - watchOS 11.5
  Android SDK: Not Found
IDEs:
  Android Studio: 2024.1 AI-241.18034.62.2412.12266719
  Xcode:
    version: 16.4/16F6
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.6
    path: /usr/bin/javac
  Ruby:
    version: 3.2.1
    path: /Users/georgejose/.rbenv/shims/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 19.1.1
    wanted: ^19.1.1
  react:
    installed: 19.0.0
    wanted: 19.0.0
  react-native:
    installed: 0.79.5
    wanted: 0.79.5
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: Not found
  newArchEnabled: Not found
iOS:
  hermesEnabled: true
  newArchEnabled: true

newrelic-react-native-agent: 1.5.5

[ndesai-newrelic]

@G2Jose can you enable this flag in agent Configuration?

 // iOS Specific
 // Optional: Enable or disable to use our new, more stable, event system for iOS agent.
 newEventSystemEnabled:false, 

https://github.com/newrelic/newrelic-react-native-agent?tab=readme-ov-file#react-native-setup

[G2Jose]

Sure, will set newEventSystemEnabled: true (was false before) and see if it changes anything. Since this seems to happen sporadically it may be some time before it's conclusive.

Is there a reason it's not the default @ndesai-newrelic?

[Jojr]

@G2Jose after you set newEventSystem Enabled: true, did the hangs logs in Sentry stop appearing?

[G2Jose]

Not a 100% sure @Jojr. I still see some app hangs, but the stack traces no longer obviously point to newrelic being the cause. It likely is unrelated.

[ndesai-newrelic]

@G2Jose We're planning to implement this change by default, as it was previously experimental until we received customer feedback. Have you attempted to disable interaction tracing?

[G2Jose]

@ndesai-newrelic I have interaction tracking turned off