Application Not Responding (ANR) feature breaks use with PM2

[joshkel]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which SDK are you using?

@sentry/node

SDK Version

7.72.0

Framework Version

No response

Link to Sentry event

No response

SDK Setup

  Sentry.init({
    dsn: process.env.SENTRY_DSN,
    release: getSentryReleaseIdentifier(),
    environment: process.env.SITE_NAME?.toLowerCase() || undefined,
    initialScope: {
      tags: { commit: version?.commitSha },
    },
  });

Steps to Reproduce

1. Enable the new Application Not Responding feature:

   await Sentry.enableAnrDetection({ captureStackTrace: true });

2. Configure the application to run within PM2.

Expected Result

The application works.

Actual Result

Sentry's ANR feature thinks that the application is the ANR watchdog child (because the process has been forked by PM2 and therefore has a process.send), so it doesn't work. (In my local testing, it causes PM2 to treat the process as terminated by SIGINT.)

I could provide a separate entryScript, but that wouldn't help the issue of the parent process thinking it's the child. I think I could delete process.send, but that seems like a hack (and can break PM2 features). Maybe enableAnrDetection needs some sort of "force" parameter? Maybe it should assume it's the parent (ignoring process.send) if an entryScript is provided and/or if entryScript !== process.arg[1]?

[AbhiPrasad]

Hey @joshkel - thanks for writing in! Your GitHub issue led us to make a bunch of improvements to the ANR tracking in #9128, so appreciate the feedback a lot.

Will update once we've released those improvements. Thanks!

[AbhiPrasad]

We've released the fix for this issue in https://github.com/getsentry/sentry-javascript/releases/tag/7.73.0. Please give it a try - feedback is welcome!