I got an error from exec() function

Tell us what’s happening:
i got the error from exec() function like this :

MongooseError: Operation urls.findOne() buffering timed out after 10000ms
at Timeout. (/home/runner/boilerplate-project-urlshortener-1/node_modules/mongoose/lib/drivers/node-mongodb-native/collection.js:184:20)

Your code so far
on repl.it :

this is my code:

const express = require('express');
const cors = require('cors');
const app = express();

const bodyParser = require("body-parser");
const mongoose = require("mongoose");

// Basic Configuration
const port = process.env.PORT || 3000;


app.use('/public', express.static(`${process.cwd()}/public`));

app.get('/', function(req, res) {
  res.sendFile(process.cwd() + '/views/index.html');

// Your first API endpoint
app.get('/api/hello', function(req, res) {
  res.json({ greeting: 'hello API' });

app.listen(port, function() {
  console.log(`Listening on port ${port}`);

    useNewUrlParser: true,
    useUnifiedTopology: true,
    useFindAndModify: false,
    useCreateIndex: true,
  () => {
    console.log("Connected to mongoDB");

let urlSchema = new mongoose.Schema({
  original: { type: String, required: true },
  short: Number,

let Url = mongoose.model("Url", urlSchema);
let responseObject = {};

  bodyParser.urlencoded({ extended: false }),
  (request, response) => {
    let inputUrl = request.body["url"];

    responseObject["original_url"] = inputUrl;

    let inputShort = 1;

      .sort({ short: "desc" })
      .exec((error, result) => {
        // the error appears

        if (!error && result != undefined) {
          inputShort = result.short + 1;
        if (!error) {
            { original: inputUrl },
            { original: inputUrl, short: inputShort },
            { new: true, upsert: true },
            (error, savedUrl) => {
              if (!error) {
                responseObject["shorten_url"] = savedUrl.short;
        } else {

Your browser information:

User Agent is: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36.

Challenge: URL Shortener Microservice

Link to the challenge:

Your’re using findOne() without any arguments, so the database doesn’t know what you’re looking for. Add some arguments for it to return the right entry.
I also see that in your repl.it, you changed it to find() which should return the whole database, that’s a lot of data transferred when you don’t need to pull the whole thing to the client side.

also, unrelated notes,:

  • you can write request.body.url instead, since the key url is always the same.
  • look into try/catch for error handling
1 Like

thank you for your reply, there actually no data in the database, for the sake of learning I don’t think that has anything to do with the current error? isn’t it?