I’m using mongoDB atlas for my MERN chat app, and getting the following error:

MongooseError: Operation `users.findOne()` buffering timed out after 10000ms
    at Timeout.<anonymous> (/Users/thakur/Desktop/web/react_app/chat-app/node_modules/mongoose/lib/drivers/node-mongodb-native/collection.js:185:23)
    at listOnTimeout (node:internal/timers:569:17)
    at process.processTimers (node:internal/timers:512:7)

I tried increasing the server timeout but it didn’t help.

indes.js

const express = require('express');
const dotenv = require('dotenv');
const mongoose = require('mongoose');
const User = require('../Models/userModel');
const userRoutes = require('../Routes/userRoutes');
const app = express();
dotenv.config();
app.use(express.json());

mongoose.set('debug', true); 

const connectDb = async () => {
    try {
        const connect = await mongoose.connect(process.env.MONGO_URL,{
        
            serverSelectionTimeoutMS: 30000, // 30 seconds
            socketTimeoutMS: 45000 // 45 seconds
        });
        console.log("Server is connected to the database");
    } catch (err) {
        console.log("Server is not connected to the database", err.message);
    }
};



connectDb();




app.get("/", (req, res) => {
    res.send('Api is running on port');
   
});

app.use("/user", userRoutes);

const PORT = process.env.PORT
app.listen(PORT, console.log('Server is running on port 5050'));

userController.js

const express = require('express');
const asyncHandler = require('express-async-handler');

const UserModel = require('../Models/userModel');

const loginController = () => {};

const registerController = asyncHandler(async (req, res) => {
  const { name, email, password } = req.body;

  // Check for all fields
  if (!name || !email || !password) {
    return res.status(400).json({ message: 'All fields are required' });
  }

  // Pre-existing user
  const userExist = await UserModel.findOne({ email });
  if (userExist) {
    return res.status(400).json({ message: 'User already exists' });
  }

  // Username already taken
  const userNameExist = await UserModel.findOne({ name });
  if (userNameExist) {
    return res.status(400).json({ message: 'Username already exists' });
  }

  // Create an entry in database for the user
  const user = await UserModel.create({ name, email, password });

  res.status(201).json(user);
});

module.exports = { loginController, registerController };