Node.js – Node / Express: EADDRINUSE, Address already in use – Kill server

node.js

I have a simple server running in node.js using connect:

var server = require('connect').createServer();
//actions...
server.listen(3000);

In my code I have actual handlers, but thats the basic idea. The problem I keep getting is

EADDRINUSE, Address already in use

I receive this error when running my application again after it previously crashed or errors. Since I am not opening a new instance of terminal I close out the process with ctr + z.

I am fairly certain all I have to do is close out the server or connection. I tried calling server.close() in process.on('exit', ...); with no luck.

Best Answer

You can also go the command line route:

ps aux | grep node

to get the process ids.

Then:

kill -9 PID

Doing the -9 on kill sends a SIGKILL (instead of a SIGTERM). SIGTERM has been ignored by node for me sometimes.

Related Solutions

Node.js – How to determine a user’s IP address in node

In your request object there is a property called socket, which is a net.Socket object. The net.Socket object has a property remoteAddress, therefore you should be able to get the IP with this call:

request.socket.remoteAddress

(if your node version is below 13, use the deprecated now request.connection.remoteAddress)

EDIT

As @juand points out in the comments, the correct method to get the remote IP, if the server is behind a proxy, is request.headers['x-forwarded-for']

Javascript – Node.js/Express.js App Only Works on Port 3000

The following works if you have something like this in your app.js:

http.createServer(app).listen(app.get('port'),
  function(){
    console.log("Express server listening on port " + app.get('port'));
});

Either explicitly hardcode your code to use the port you want, like:

app.set('port', process.env.PORT || 3000);

This code means set your port to the environment variable PORT or if that is undefined then set it to the literal 3000.

Or, use your environment to set the port. Setting it via the environment is used to help delineate between PRODUCTION and DEVELOPMENT and also a lot of Platforms as a Service use the environment to set the port according to their specs as well as internal Express configs. The following sets an environment key=value pair and then launches your app.

$ PORT=8080 node app.js

In reference to your code example, you want something like this:

var express = require("express");
var app = express();

// sets port 8080 to default or unless otherwise specified in the environment
app.set('port', process.env.PORT || 8080);

app.get('/', function(req, res){
    res.send('hello world');
});

// Only works on 3000 regardless of what I set environment port to or how I set
// [value] in app.set('port', [value]).
// app.listen(3000);
app.listen(app.get('port'));

Best Answer

Related Solutions

Node.js – How to determine a user’s IP address in node

Javascript – Node.js/Express.js App Only Works on Port 3000

Related Topic