User Feedback: Node.js Vercel logs not recorded in Sentry

[linear]

Sentry Feedback: JAVASCRIPT-33GA

logs emitted from nodejs app hosted on Vercel are not getting recorded in Sentry. It seems to happen when console.log is called more than once within a vercel function.

[linear]

JS-954 User Feedback: Node.js Vercel logs not recorded in Sentry

[awei82]

👋 I submitted this feedback. I submitted a zendesk ticket with more details as well - reference number 162763.

My guess as to what is going on is maybe Vercel is shutting the function down before the Sentry SDK has a chance to flush its logs?

[awei82]

FYI I just upgraded my Sentry version from 9.43.0 -> 10.12.0. Some more logs are being captured, but others are still missing...

[AbhiPrasad]

but others are still missing

are you able to tell what kind of logs are missing? is there a consistent pattern here?

@awei82 If you share your node.js version, we can try reproducing this! Are you using any kind of framework, or just a plain Node.js app?

[mydea]

I wonder if this: #17583 will/would fix this. You could try it yourself by adding this to your app:

process.on('SIGTERM', () => {
  Sentry.flush(200);
});

And see if that fixes things?

[awei82]

Hi @AbhiPrasad - it seems to miss logs when multiple console.log calls are being called within one Vercel function call - the first log statement will be captured, but remaining gets missed. It seems to happen randomly, or just on certain endpoints, but I can't figure out why.

Vercel is running Node 22.x. I'm using Sveltekit: "@sveltejs/kit": "^2.16.0"

@mydea this seems to be fixing the problem 👍 - I'll need to test more to confirm though.