NextJS 13 returns fetch failed with UND_ERR_CONNECT_TIMEOUT after running in production mode for a day

[prunusnira]

Summary

Environment

next 13.4
node 18.16.0
running with pm2

Problem

Sometimes nextjs freezes and stop responding. (on production mode, we found that after running for 23 hours)
it returns 500 Internal Server Error on browser, and UND_ERR_CONNECT_TIMEOUT on server.
for me, it does not look like memory leak problem because pm2 says it uses memory under 100MB
When this happens, even pm2 does not restart automatically. it detects nextjs as status: online

Check additional information for detailed server error

is there someone who have same problem? or any workaround on this?

I can't post code because it is already too big code bases and security issue

Additional information

detailed error

TypeError: fetch failed
    at Object.fetch (node:internal/deps/undici/undici:11457:11)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async invokeRequest (/opt/mall-front/node_modules/next/dist/server/lib/server-ipc/invoke-request.js:17:12)
    at async invokeRender (/opt/mall-front/node_modules/next/dist/server/lib/router-server.js:254:29)
    at async handleRequest (/opt/mall-front/node_modules/next/dist/server/lib/router-server.js:447:24)
    at async requestHandler (/opt/mall-front/node_modules/next/dist/server/lib/router-server.js:464:13)
    at async Server.<anonymous> (/opt/mall-front/node_modules/next/dist/server/lib/start-server.js:117:13) {
  cause: ConnectTimeoutError: Connect Timeout Error
      at onConnectTimeout (/opt/mall-front/node_modules/next/dist/compiled/undici/index.js:1:82152)
      at /opt/mall-front/node_modules/next/dist/compiled/undici/index.js:1:81644
      at Immediate._onImmediate (/opt/mall-front/node_modules/next/dist/compiled/undici/index.js:1:82034)
      at process.processImmediate (node:internal/timers:476:21) {
    code: 'UND_ERR_CONNECT_TIMEOUT'
  }

environment

    Operating System:
      Platform: linux
      Arch: x64
      Version: #1 SMP PREEMPT_DYNAMIC Tue Jun  6 00:47:06 UTC 2023
    Binaries:
      Node: 18.16.0
      npm: 9.5.1
      Yarn: 1.22.19
      pnpm: N/A
    Relevant Packages:
      next: 13.4.19
      eslint-config-next: 13.4.3
      react: 18.2.0
      react-dom: 18.2.0
      typescript: 5.2.2
    Next.js Config:
      output: N/A

### Example

_No response_

[ADTC]

Next.js 14 removes undici. Try upgrading.

[prunusnira]

is it safe to use 14 in production rn? 😣

[ADTC]

If all your tests pass I don't see a problem. Note though that it requires Node 18 and above.

Btw, it should be noted that the native fetch inside Node 18+ is undici so I don't guarantee this problem will go away. But it's worth a shot. (See #57875 for more info.)

[ADTC]

Note: https://nextjs.org/blog/next-14

Minimum Node.js version is now 18.17

I see that your Node is one step too old at 18.16. You'll have to upgrade that too.

[prunusnira]

after updated our project to 14.0.1, at least we didn't see any undici related error. thanks
(currently going to 14.0.3 to fix other bug)

[muhammad-rizwan1]

Hi,
not sure if I have to raise a new question or continue with this as I'm having undici related error as well.

My Next.js version 14.2.3 and Node v20.11.1 but still getting the error,

digest: "3554945235"
Cause: ConnectTimeoutError: Connect Timeout Error
    at onConnectTimeout (node:internal/deps/undici/undici:7492:28)
    at node:internal/deps/undici/undici:7448:50
    at Immediate._onImmediate (node:internal/deps/undici/undici:7478:37)
    at process.processImmediate (node:internal/timers:478:21)
    at process.callbackTrampoline (node:internal/async_hooks:130:17) {
  code: 'UND_ERR_CONNECT_TIMEOUT'
} 

[alarm109]

Me too. We are using Vercel, in the logs I see that some request go through without errors. Others have one or two of these TypeError: fetch failed, UND_ERR_CONNECT_TIMEOUT.

"next": "14.1.2"
"node": ">=18.17.0"

TypeError: fetch failed
    at node:internal/deps/undici/undici:12345:11
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at runNextTicks (node:internal/process/task_queues:64:3)
    at process.processImmediate (node:internal/timers:449:9)
    at process.topLevelDomainCallback (node:domain:160:15)
    at process.callbackTrampoline (node:internal/async_hooks:128:24)
    at async globalThis.fetch (/var/task/node_modules/.pnpm/next@14.1.2_@babel+core@7.24.0_react-dom@18.2.0_react@18.2.0/node_modules/next/dist/compiled/next-server/app-route.runtime.prod.js:6:36091) {
  cause: ConnectTimeoutError: Connect Timeout Error
      at onConnectTimeout (node:internal/deps/undici/undici:7492:28)
      at node:internal/deps/undici/undici:7448:50
      at Immediate._onImmediate (node:internal/deps/undici/undici:7480:13)
      at process.processImmediate (node:internal/timers:478:21)
      at process.topLevelDomainCallback (node:domain:160:15)
      at process.callbackTrampoline (node:internal/async_hooks:128:24) {
    code: 'UND_ERR_CONNECT_TIMEOUT'
  }
}