How to resolve `buffering timed out after 10000ms` error in MongodoDB and Mongoose

Question

I am using MongoDb in my Nodejs App with mongoose as ORM. However I am getting this error everytime I run my code.

(node:28316) UnhandledPromiseRejectionWarning: MongooseError: Operation `auths.findOne()` buffering timed out after 10000ms
    at Timeout.<anonymous> (/home/mridu/Projects/unoletter/node_modules/mongoose/lib/drivers/node-mongodb-native/collection.js:149:23)
    at listOnTimeout (internal/timers.js:557:17)
    at processTimers (internal/timers.js:500:7)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:28316) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)
(node:28316) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Here is my code to connect with MongoDb atlast

try {
  mongoose.connect(
    process.env.DB_URI,
    {
      keepAlive: true,
      useNewUrlParser: true,
      useUnifiedTopology: true,
      useFindAndModify: false,
    },
    () => {
      console.log(`connected to MongoDB`);
    }
  );
} catch (error) {
  console.log(error);
}

My model

//Dependencies
const mongoose = require("mongoose");

//Auth Model
const auth = {
  id: {
    type: String,
    required: true,
  },
  email: {
    type: String,
    required: true,
  },
  secret: {
    type: String,
    required: true,
  },
  isVerified: Boolean,
  createdAt: {
    time: String,
    date: String,
  },
};
const Auth = mongoose.model("Auth", auth);

//Export
module.exports = { Auth };

And this is how I am saving my data

const auth = new Auth({
      id: generateId(),
      email: body.email,
      secret: generateSecret(),
      isVerified: false,
      createdAt: {
        time: dayjs().format("HH:mm:ss"),
        date: dayjs().format("YYYY/MM/DD"),
      },
    });


try {
  await auth.save();

  console.log(auth);
} catch (error) {
  console.log(error);
}
    

I have tried some answers from Stackoverflow and other websites like Dev.to. I have tried using async/await, .then & .catch. Still I am facing the same error.

Another project where I am using the 5.xx version of Mongoose is working fine. I am facing this issue with new 6.0.3 version of mongoose.

Answer 1

Make sure to call the function that uses the connection, an example can be the following. I have the following function:

const start = async () => {
    try {
        await connectDB(process.env.MONGO_URI);
        await Product.deleteMany();
        await Product.create(jsonProducts);
        // console.log(jsonProducts)
        console.log('Conexion exitosa')
        process.exit(0)
    } catch (e) {
        console.log(e)
        process.exit(1)
    }
}

It turned out that I was declaring the function but not using it, my solution was just to execute the start() function.