Weird socket.io / EventEmitter issue

[drochag]

While running my server, I might have a lot of objects listening on socket.io (not perfectly sure how it works, 2nd time implementing it) and I'm having this

// Terminal
 Waiting...
(node) warning: possible EventEmitter memory leak detected. 11 disconnect listeners added. Use emitter.setMaxListeners() to increase limit.
Trace
    at Socket.addListener (events.js:179:15)
    at Object.exports.register (/Users/dan/Documents/projects/centro/server/api/saleProduct/saleProduct.socket.js:19:12)
    at onConnect (/Users/dan/Documents/projects/centro/server/config/socketio.js:25:52)
    at Namespace.<anonymous> (/Users/dan/Documents/projects/centro/server/config/socketio.js:71:5)
    at Namespace.emit (events.js:107:17)
    at Namespace.emit (/Users/dan/Documents/projects/centro/node_modules/socket.io/lib/namespace.js:205:10)
    at /Users/dan/Documents/projects/centro/node_modules/socket.io/lib/namespace.js:172:14
    at process._tickCallback (node.js:355:11)
[undefined:52218] CONNECTED

that line is the one having socket.on('disconnect' … here

// saleProduct.socket.js
exports.register = (socket) => {
  // Bind model events to socket events
  for (let i = 0, eventsLength = events.length; i < eventsLength; i++) {
    let event = events[i];
    let listener = createListener('saleProduct:' + event, socket);

    SaleProductEvents.on(event, listener);
    socket.on('disconnect', removeListener(event, listener));
  }
};

but the event emitter already has this SaleProductEvents.setMaxListeners(0); on saleProduct.events.js so not sure what could I be doing wrong.

[kingcody]

So you're saying that this: saleProduct.socket.js:19:12 is this: socket.on('disconnect', removeListener(event, listener));?

If you could provide a link to your source, that would be really helpful.

[drochag]

https://bitbucket.org/DanMMX/casacuestacentro

@kingcody

[kingcody]

@danmmx sorry for the delay. This issue is not with your saleProduct eventEmitter but the socket.io EE, which I'm sure you've realized. We only set the maxListeners(0) on our custom endpoint EE's, so you'll need to do the same for your socket.io EE.

A good place to do that might be here (server/config/socketio.js):

module.exports = function(socketio) {
  // socket.io (v1.x.x) is powered by debug.
...
  socketio.on('connection', function(socket) {
    socket.setMaxListeners(20);  // Set the client's socket.io EE to max listeners: 20
    // socket.setMaxListeners(0);  // Set the client's socket.io EE to max listeners: unlimited
    socket.address =
      socket.handshake.address !== null ?
      socket.handshake.address.address + ':' + socket.handshake.address.port :
      process.env.DOMAIN;
...
};

[drochag]

Thanks a lot @kingcody , I thought with the config on each model's EventEmitter was enough. This fixed it.

[kingcody]

No problem, glad to hear it (: