Creating all serverless functions taking 5+ mins

[akshitkrnagpal]

Hi everyone

I am facing this issue on Vercel that builds are taking 10+mins more than half of the time is for creating serverless functions.

Created all serverless functions in: 6:13.097 (m:ss.mmm)

As I am not using getServerSideProps for any page I don't think serverless function needs to be created. That is confirmed from the functions tab of vercel because it shows "No Serverless Functions"

How can find the cause of this?

[ijjk]

Hi, can you test the latest version of Next.js v11.1.3-canary.91 and add the below config to your next.config.js? We're working on improving the performance/reliability of this step in the latest version.

module.exports = {
  experimental: {
    outputFileTracing: true
  }
}

[akshitkrnagpal]

Hi @ijjk

Yes. I tried the above changes and the build time went from 10mins to 4 mins. Creating all serverless functions reduced from 6 mins to 2 secs. But I noticed some of the pages were giving 500 error in deployed build (on vercel) whereas they working fine on dev and production build on my localhost. The issue seems to be if the page was to be generated by fallback: "blocking", it was giving 500 error on Vercel. (Not during build time, but when visiting the page).

Do you know how this can be fixed?

[ijjk]

Can you share a link to the repo or to the deployment so we can investigate this further?

[akshitkrnagpal]

@ijjk I cannot share as it's a company project and we wouldn't like that to be shared in public right now. Can I DM you on twitter?

[ijjk]

Yes, feel free to DM https://twitter.com/_ijjk

[akshitkrnagpal]

@ijjk Thanks. DM'd you.

[rodilo]

hey @akshitkrnagpal @ijjk
I think we have the same issue, I did some debugging and you can check it here
#30255
There's also a test repo I've used for debugging.

Basically, for us, it happens because of i18n. We don't have any pages with getServerSideProps or getInitialProps.
I tested some older versions of next, and this thing started happening after 10.1.*

Our production app is a bit complex, and usually, it takes around 5-6 minutes to deploy on vercel. But after an upgrade to next 11, it takes as twice as long.

[akshitkrnagpal]

Hi @rodilo

Have you tried the following suggestion from ijjk? What was your result?

Hi, can you test the latest version of Next.js v11.1.3-canary.91 and add the below config to your next.config.js? We're working on improving the performance/reliability of this step in the latest version.

module.exports = {
  experimental: {
    outputFileTracing: true
  }
}

[rodilo]

@akshitkrnagpal yes, just now, I've got this error:

[ijjk]

@rodilo which deployment are you seeing that error? The linked reproduction is showing a successful deploy without that error being present rodilo/next-18n-build-test@d8e5858

[ijjk]

That error usually only occurs when you have incorrect build settings under your project's settings. It might say Other instead of Next.js or have an incorrect output directory.

[rodilo]

@rodilo which deployment are you seeing that error? The linked reproduction is showing a successful deploy without that error being present rodilo/next-18n-build-test@d8e5858

It happened on my private project (the one that takes 15 minutes to build). This test project run ok.

Yes, the build config on my private project is set to Other, I'll change that and try again. Thanks for the help 👍

[rodilo]

@ijjk

OK, it works now, build runs in a reasonable time (~5 minutes instead of ~16-17).
I've found what was causing the issue with the build failing.
I use this code for getting dynamic slugs:

import matter from 'gray-matter'
import path from 'path'
import read from 'read-directory'

const raw = read.sync(path.join(process.cwd(), 'data/postItems'), { transform: matter })

and it works when I run next dev but it doesn't in next build. .
The problem is this read-directory package, so I've created my own function that does the same.

Other more important thing that it's not working are pages with getServerSideProps. I get 500 error and this when I try to check function logs on vercel:

You can check that on this preview link https://emmalife-p7vs2uf5e-creadi.vercel.app/feedback

Hope this helps. I'm looking forward to releasing this feature.

[ijjk]

The error you encountered viewing the logs should be corrected, it seems the 500 error is being caused by @sentry/nextjs specifically this file /var/task/node_modules/@sentry/nextjs/dist/utils/instrumentServer.js:7:14 as it tries to import the entire next module which we don't allow since it would increase the deployment size drastically.

[rodilo]

The error you encountered viewing the logs should be corrected, it seems the 500 error is being caused by @sentry/nextjs specifically this file /var/task/node_modules/@sentry/nextjs/dist/utils/instrumentServer.js:7:14 as it tries to import the entire next module which we don't allow since it would increase the deployment size drastically.

And what about my test repo? I added getServerSideProps to one page, and I got the same error - 500, check it here:

https://next-18n-build-test-6g8yx03yk-shonely.vercel.app/second-page

In the functions log i get this:

[ijjk]

That issue looks related to i18next/next-i18next#1202 (comment) you can work around that by adding a fs.readdir(path.join(process.cwd(), 'public/locales') to your getServerSideProps where serverSideTranslations is being used.

[rodilo]

Ah, those were two different things.
@ijjk thanks for your help, now I need to figure out what to do with sentry :)

[ijjk]

Could use patch-package and comment out this call also removing the import which should resolve it temporarily although would be good to open an issue for the package.