The MongoDb driver, sometimes, does not reconnect automatically. My application simply just stop working because the driver didn't reconnected. If I restart the application it works properly.

I've made a simples script to test it.

const mongodb = require('mongodb');
const MongoClient = mongodb.MongoClient;

function randomIndex() {
  return Math.ceil(Math.random() * 2100);
}

MongoClient.connect('mongodb://localhost/somedb').then(db => {
  let collection = db.collection('somecollection');
  db.on('close', err => console.log('close', err));
  db.on('reconnect', () => console.trace('reconnect'));

  setInterval(() => {
    collection.find({
      index: randomIndex()
    }).limit(1).next()
      .then(console.log)
      .catch(console.log);
  }, 1000);
});

Steps to reproduce the error:

• Start mongodb
• Start script
• Stop mongodb
• Restart mongodb
• Stop mongodb
• Restart mongodb

After restarting it for the second time, my application running on node does not reconnect to mongo.

I think I have found the solution for this and made a pull request https://github.com/christkv/mongodb-core/pull/78.

I would like you to check if my solution is valid.

Thanks