Nodejs & socket io : warn - error raised: Error: listen EADDRINUSE

Question

I am giving a try to Node.js with socket.io

Now here is my scenario i am ubuntu 12.04 user and i have folder pp on desktop

inside that i am putted server f

Answer 1

You are not connecting to your server, this is wrong:

var iosocket = io.connect();

this is right:

var iosocket = io.connect('http://localhost:8080');

Also your port 8080 is used on your server by "http-proxy", try an other port.

Answer 2

An ultra-silly/simple possibility is to make sure you don't have multiple terminal windows open. I got this error and realized I had a second pre-existing connection that I had started up my app with. When I closed it and restarted the app the error went away.

Answer 3

Here is an example for beginners of how you can set up NodeJS + Express + SocketIO so that you have no EADDRINUSE error for the second time you start your app:

'use strict';

// Init
var http = require('http');
var express = require('express');
var socketIO = require('socket.io');
var cors = require('cors');

// Create Server app
var app = express();
var server = http.createServer(app);
var io = socketIO(server);

// Socket.io settings
io.set('browser client minification', true);
io.set('browser client etag', true);
io.set('browser client gzip', true);
io.set('browser client expires', true);

// Starting Express server
server.listen(serverPort, function() {
  console.log(chalk.green('Server is running on localhost:' + serverPort + '...'));
});

// Middleware
app.use(cors());

// Routes
app.get('/', function(req, res) {
    res.send("Hello world!");
    console.log("Root visited!");
    // Broadcast socketIO message inside Express
    io.emit('new_message', "Hello world!");
});

// Socket.io
var connections = [];
var title = "Untitled";

io.sockets.on('connection', (socket) => {

    socket.once('disconnect', () => {
        connections.splice(connections.indexOf(socket), 1);
        socket.disconnect();
        console.log('Disconnected: %s. Remained: %s.', socket.id, connections.length)
    });

    // ...

    connections.push(socket);
    console.log('Connected: %s. Total: %s', socket.id, connections.length);
});

I think this is a useful example and I hope it will help someone who encountered a problem setting this all up.

Answer 4

It looks to me that your not connecting to the host on the client side:

var iosocket = io.connect('http://localhost:8080');

Answer 5

Try another port. 8080 is usually used by tomcat e.g.

Use netstat -a -v to know which port are currently used.