Http-Shutdown

Shutdown a Nodejs HTTP server gracefully by doing the following:

1. Close the listening socket to prevent new connections
2. Close all idle keep-alive sockets to prevent new requests during shutdown
3. Wait for all in-flight requests to finish before closing their sockets.
4. Profit!

Other solutions might just use server.close which only terminates the listening socket and waits for other sockets to close - which is incomplete since keep-alive sockets can still make requests. Or, they may use ref()/unref() to simply cause Nodejs to terminate if the sockets are idle - which doesn't help if you have other things to shutdown after the server shutsdown.

http-shutdown is a complete solution. It uses idle indicators combined with an active socket list to safely, and gracefully, close all sockets. It does not use ref()/unref() but, instead, actively closes connections as they finish meaning that socket 'close' events still work correctly since the sockets are actually closing - you're not just unrefing and forgetting about them.

Installation

$ npm install http-shutdown

Usage

There are currently two ways to use this library. The first is explicit wrapping of the Server object:

// Create the http server
var server = require('http').createServer(function(req, res) {
  res.end('Good job!');
});

// Wrap the server object with additional functionality.
// This should be done immediately after server construction, or before you start listening.
// Additional functionailiy needs to be added for http server events to properly shutdown.
server = require('http-shutdown')(server);

// Listen on a port and start taking requests.
server.listen(3000);

// Sometime later... shutdown the server.
server.shutdown(function() {
  console.log('Everything is cleanly shutdown.');
});

The second is implicitly adding prototype functionality to the Server object:

// .extend adds a .withShutdown prototype method to the Server object
require('http-shutdown').extend();

var server = require('http').createServer(function(req, res) {
  res.end('God job!');
}).withShutdown(); // <-- Easy to chain. Returns the Server object

// Sometime later, shutdown the server.
server.shutdown(function() {
  console.log('Everything is cleanly shutdown.');
});