Impossible to connect to a MongoDB Deployment

I have a simple NodeJS project which is supposed to connect to a MongoDB server:

const express        = require('express');
const MongoClient    = require('mongodb').MongoClient;
const bodyParser     = require('body-parser');
const db             = require('./config/db');

const app            = express();

const port = 8030;

app.use(bodyParser.urlencoded({ extended: true }));
console.log(db.url)
MongoClient.connect(db.url, (err, database) => {
    if(err) return console.log(err)

    require('./app/routes')(app, database);
    app.listen(port, () => {
        console.log('Server is listenning on port 8030....');
    });
});

variable db.url contains mongodb://test:test@ds147421.mlab.com:47421/testnode where test is a database user username and test is his password.

I have this error thrown:

{ [MongoError: failed to connect to server [ds062919.mlab.com:62919] on first connect [MongoError: connection 0 to ds062919.mlab.com:62919 timed out]]
  name: 'MongoError',
  message: 'failed to connect to server [ds062919.mlab.com:62919] on first connect [MongoError: connection 0 to ds062919.mlab.com:62919 timed out]' }

I don't know what I've done wrong here.

Any idea ?

via Baptiste Arnaud