I'm looking for an event that allow me to shutdown the application in case all mongos become unavailable.
For example, with mongodb running in localhost on 27018, I run mongos with this command:
```
mongos --port 27018 --configdb 127.0.0.1:27017 -vvvvv
```
with this code:
```
'use strict';

var mongodb = require('mongodb');
var MongoClient = mongodb.MongoClient;
var Logger = mongodb.Logger;

var url = 'mongodb://localhost:27018/gamearena';
MongoClient.connect(url, {server: { }} function(err, db) {
db.collection('_User').find({})
.toArray(function(err, users)

);
db.on('error', console.log.bind(console, 'ERROR'));
db.on('close', console.log.bind(console, 'CLOSE'));
db.on('timeout', console.log.bind(console, 'TIMEOUT'));
});
```
No events are emitted when i kill mongos

Instead, if the code is connected to mongodb directly and kill mongo, the code is notified correctly.

I suppose this behavior is not right.
Which event should I listen?