Callbacks Stop Happening

I’ve been using mongoose for a few years, but lately I’m having a lot of trouble where the connection seems to disappear.

Connection Settings

// Connecting to MongoDB 3.2.1
var connString = "mongodb://xxxxx:xxxxx@xxxxx:xxxx,xxxx:xxxx/xxx?ssl=true";
var connOptions = {
  "mongos": { "ssl": true, "sslValidate": false }
};
mongoose.connect(connString, connOptions, function(err, db) {
  if(err) { console.log("Error connecting to db: "+err); }
});

The Problem

Mongoose just stops calling back. It doesn’t emit any errors, memory/cpu is fine on my server & db, and I can connect from any other server. Restarting always fixes it:

db.Something.count({}, callback);

Versions

On mongoose 4.4.11, mongoose.connection.readyState === UNAUTHORIZED when callbacks stop.

So I upgraded to mongoose 4.6.0 but within 4 hours the callbacks stopped again, now with mongoose.connection.readyState === CONNECTED.

Any Ideas

Any ideas how I can get this to stop happening?

I’m happy to gather any more debugging info, just let me know what info to get.

[vkarpov15]

Unfortunately gonna have to push this one back again because mongodb driver is held up from releasing. Sorry about that and thanks for your patience 👍 🌴

[adriaanmeuris]

thanks for testing! Indeed Mongoose always stays connected, but callbacks stop happening (you can see the request coming into Express, but they’ll timeout)

I was testing with:

• node 6.8.1
• mongodb 2.2.30
• mongoose 4.11.5

I’ve updated to:

• node 6.8.1
• mongodb 2.2.31
• mongoose 4.11.7

I can still reproduce the issue locally with the first script I posted. It only occurs when a Mongo connection times out, so you might want to change the query that simulates this:

mongoose.model('Test').find({$where: 'sleep(10000) || true'})

(I’m not sure if this will trigger a timeout on every machine so a change to this query might be necessary to reproduce)