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

Question

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.

Answer 1

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. }); 

Answer 2

To set keepAliveTimeout on the express server do:

var express = require('express'); var app = express(); var server = app.listen(5001);  server.keepAliveTimeout = 30000;