Vercel Serverless Function (Next.js API Handler) 504: Gateway time-out

[BluSimmon]

Bug description

I use Prisma with MongoDB.
Everything on my local test is fine.
But when I host the website to Vercel.
The API function will get timeout by reaching 10s execution duration limit.
And after debug, I found the problem with the code below:

const user = await prisma.user.findFirst({
    where: {
      OR: [
        {
          username: {
            equals: username,
            mode: 'insensitive'
          }
        },
        {
          email: {
            equals: username,
            mode: 'insensitive'
          }
        },
      ]
    },
    select: {
      username: true,
      email: true,
      password: true,
      role: true,
    }
  })

How to reproduce

You can have a test with https://test-prisma-login.vercel.app/
(You can input fields freely)

Expected behavior

No response

Prisma information

generator client {
  provider = "prisma-client-js"
}

datasource db {
  // MongoDB: ZunicMC > ZunicWeb
  provider = "mongodb"
  url      = env("DATABASE_URL")
}

model User {
  id       String   @id @default(auto()) @map("_id") @db.ObjectId
  username  String  @unique
  email     String  @unique
  password  String  
  role      Role    @default(USER)
  profile   Profile?
}

model Profile {
  id     String   @id @default(auto()) @map("_id") @db.ObjectId
  user    User    @relation(fields: [userId], references: [id])
  userId  String  @db.ObjectId @unique
}

enum Role {
  USER
  ADMIN
  OWNER
}

Environment & setup

• OS (development): Windows
• Database: MongoDB
• Node.js version: v18.16.1

Prisma Version

prisma                  : 5.3.1
@prisma/client          : 5.3.1
Current platform        : windows
Query Engine (Node-API) : libquery-engine 61e140623197a131c2a6189271ffee05a7aa9a59 (at node_modules\@prisma\engines\query_engine-windows.dll.node)
Schema Engine           : schema-engine-cli 61e140623197a131c2a6189271ffee05a7aa9a59 (at node_modules\@prisma\engines\schema-engine-windows.exe)
Schema Wasm             : @prisma/prisma-schema-wasm 5.3.1-2.61e140623197a131c2a6189271ffee05a7aa9a59
Default Engines Hash    : 61e140623197a131c2a6189271ffee05a7aa9a59
Studio                  : 0.494.0

[janpio]

What is the problem you found in that code?
Does other code work and just this query is broken?
Where are you hosting your MongoDB instance?

[BluSimmon]

The code execute with a long time, it reach the execution duration limit of Vercel plan.
Everything is work, just the execution time is out of limit.
I host the MongoDB with MongoDB Cloud.

[janpio]

That sounds like your MongoDB database might not actually be accessible from the Vercel function.
Are your sure that your database should be accessible from that function?

[BluSimmon]

The project's environment variables and schema database connection url are setted correctly.
But there isn't any error that i can see from the build log.
This is all I can see from vercel:

[janpio]

Do you have to whitelist the requesting IP on the MongoDB side?
No logs on Vercel?

[BluSimmon]

Oh, it is sorry that for my mistake.
The solution is to allow access from everywhere from MongoDB.
Thank you for your helps!

[GeorgeArubi]

This discussion post just saved me, thank you so much