next.js: MaxListenersExceededWarning
Verify canary release
- I verified that the issue exists in the latest Next.js canary release
Provide environment information
NOTE: Installing next@canary caused a bunch of `ERESOLVE` errors, so I have not tested with it
Operating System:
Platform: linux
Arch: x64
Version: #1 SMP Fri Jan 27 02:56:13 UTC 2023
Binaries:
Node: 20.5.1
npm: 9.8.0
Yarn: 1.22.15
pnpm: 6.11.0
Relevant Packages:
next: 13.4.20-canary.15
eslint-config-next: 13.4.12
react: 18.2.0
react-dom: 18.2.0
typescript: 5.1.6
Next.js Config:
output: N/A
Which area(s) of Next.js are affected? (leave empty if unsure)
No response
Link to the code that reproduces this issue or a replay of the bug
https://github.com/Sage-Future/fatebook/tree/revision-test
To Reproduce
Push to vercel and load page
Issue deployment here https://vercel.com/sage-org/forecast-bot/6CiFTtcpywgQBwxYUpPJHTVQwZPz
Describe the Bug
We pushed a new version of our app to production today and started seeing “MaxListenersExceededWarning” warnings.
What we tried:
- “Instant rollback” made the warnings stop, however
- forking the code identical to the rolled back commit and deploying to a new branch still had the warnings
- Updating the deploy install command to
npm ciand clearing the build cache didn’t help
I figured out how to get a stack trace for the warnings, and this is what we see:
(node:8) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 response listeners added to [ClientRequest]. Use emitter.setMaxListeners() to increase limit
MaxListenersExceededWarning
Possible EventEmitter memory leak detected. 11 response listeners added to [ClientRequest]. Use emitter.setMaxListeners() to increase limit
MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 response listeners added to [ClientRequest]. Use emitter.setMaxListeners() to increase limit
at _addListener (node:events:588:17)
at ClientRequest.prependListener (node:events:620:14)
at ClientRequest.prependOnceListener (node:events:665:12)
at mod.request (/var/task/___vc/__launcher.js:190:13)
at Bridge.handleEvent (/var/task/___vc/__launcher.js:617:31)
at async Bridge.launcher [as handler] (/var/task/___vc/__launcher.js:474:26)
My guess is this __launcher.js:190:13 has been updated in the last couple days and this is causing the issue. We don’t see the warnings when we use “instant rollback” as I assume it’s using a cached version of launcher.js
I can see 2 other issues potentially related, https://github.com/vercel/next.js/issues/53949 and https://github.com/vercel/next.js/issues/54104
Expected Behavior
Our logs not being full of memory leak warnings
Which browser are you using? (if relevant)
No response
How are you deploying your application? (if relevant)
vercel
About this issue
- Original URL
- State: closed
- Created 10 months ago
- Reactions: 12
- Comments: 29 (3 by maintainers)
Hi everyone! This was an issue we detected in our runtime and was already fixed. You can re-deploy to Vercel or re-run your deployment and the problem should be gone. Please reopen in case it keeps happening. Sorry about the inconvenience! 🙏
I just created a support case on Vercel: https://vercel.com/help I will update in here if I hear anything.
I do have the same problem and rolling back didn’t work for me unfortunately. This issue should be reopened.
Seeing lots of these errors rolling into our Vercel logs in the past 30 mins or so.
We also ran into this starting with yesterday’s deploy
Same here in our account “artisan-labs” my project is “brisas-titicaca” Same logs
MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 response listeners added to [ClientRequest]This also began happening ~2 hours ago. All was good yesterday.
(node:8) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 response listeners added to [ClientRequest]. Use emitter.setMaxListeners() to increase limitI do have the same:
(node:8) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 response listeners added to [ClientRequest]. Use emitter.setMaxListeners()Seeing this as well
Same issue here. I have opened a support case with Vercel and I would suggest anyone experiencing the problem to do the same, as this is likely an issue with their environment.
Also having this issue.
We’re seeing the same issue.
We see MaxListenersExceededWarning errors from many severless functions.
It happens only to deployments after today 4:30 pm (Singapore time). We instant rollbacked to previous build and it works fine without errors.
(node:15) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 response listeners added to [ClientRequest]. Use emitter.setMaxListeners() to increase limitFacing the exact same issue as others. So not sure what that supposed fix is.
I can’t provide a repo as it’s our entire codebase, and don’t have the time to try create a reproduction that is smaller. If I knew what was causing it I’d fix it.
I’m using Prisma with data proxy as a best guess but actually have no idea what’s causing it.
@filmerjarred @Renetnielsen @san-pblr-gct @DB-Alex Y’all need to provide some valid repros. Sharing logs or undeployable repos doesn’t help to fix this issue.