How to set the HTTP Keep-Alive timeout in a nodejs server

express, http-headers, keep-alive, node.js

Solution

For Express 3:

var express = require('express');
var app = express();
var server = app.listen(5001);

server.on('connection', function(socket) {
  console.log("A new connection was made by a client.");
  socket.setTimeout(30 * 1000); 
  // 30 second timeout. Change this as you see fit.
});

Problem

I'm actually doing some load testing against an ExpressJS server, and I noticed that the response send by the server includes a "Connection: Keep-Alive" header. As far as I understand it, the connection will remain opened until the server or the client sends a "Connection: Close" header. In some implementations, the "Connection: Keep-Alive" header comes up with a "Keep-Alive" header setting the connection timeout and the maximum number of consecutive requests send via this connection. For example : "Keep-Alive: timeout=15, max=100" Is there a way (and is it relevant) to set these parameters on an Express server ? If not, do you know how ExpressJS handles this ? Edit: After some investigations, I found out that the default timeout is set in the node standard http library: ``` socket.setTimeout(2 * 60 * 1000); // 2 minute timeout ``` In order to change this: ``` var http = require('http'); http.createServer(function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end("Hello World"); }).on('connection', function(socket) { socket.setTimeout(10000); }).listen(3000); ``` Anyway it still looks a little bit weird to me that the server doesn't send any hint to the client concerning its timeout. Edit2: Thanks to josh3736 for his comment. setSocketKeepAlive is not related to HTTP keep-alive. It is a TCP-level option that allows you to detect that the other end of the connection has disappeared.

Original source