Node.js sockets

basicpool.js

// Create the http handler
var http = require('http');

// Set the http protocol to have 10 sockets
http.globalAgent.maxSockets = 10;

differentprotocols.js

// Create the http and https handlers
var http = require('http'),
    https = require('https');

// Set the http protocol to have 10 sockets
http.globalAgent.maxSockets = 10;

// Set the https protocol to have 12 sockets
https.globalAgent.maxSockets = 12;

globalAgent.js

// http.globalAgent
{ options: {},
  requests: {
    'host': [
      array of client requests (http://nodejs.org/api/http.html#http_class_http_clientrequest)
    ]
  },
  sockets: {
    'host': [
      array of net sockets (http://nodejs.org/api/net.html#net_class_net_socket)
    ]
  },
  maxSockets: 5, // Global maximum
  _events: { free: [Function] },
  createConnection: [Function]
}

instances.js

// Create the http and http2 handler
var http = require('http'),
    http2 = require('http');

// Set the main global agent
http.globalAgent.maxSockets = 25;

// Set the instance of http to have 10 sockets
http.Agent.maxSockets = 10;

// Set the instance of http2 to have 15 sockets
http2.Agent.maxSockets = 15;

nodejsSockets.js

// Some socket helpers
var sockets = {	
	// How many are in use altogether
	inUse: function(http){
		// Set default to 0
		var httpPool = 0;
		
		var socketList = http.globalAgent.sockets;
		
		// For each socket
		for(var socket in socketList){
			if(socketList.hasOwnProperty(socket)){
				// Add the number of sockets
				httpPool += socketList[socket].length;
                                /*
                                 * Note that each item in socketList[socket] is an instance
                                 * of a net socket (http://nodejs.org/api/net.html#net_class_net_socket)
                                 */
			}
		}
		
		return httpPool;
	},
	
	// Which hosts are we connected to
	hosts: function(http){
		var hosts = [];
		
		var socketList = http.globalAgent.sockets;
		
		for(var socket in socketList){
			if(socketList.hasOwnProperty(socket)){
				hosts.push(socket);
			}
		}
		
		return hosts;
	}
};

// Usage
// Log the number of connections in use
console.log(socket.inUse(http));
// Hosts connected to
console.log(sockets.hosts(http));

shared.js

// Create the http and http2 handler
var http = require('http'),
    http2 = require('http');

// Set the instance of http to have 10 sockets
http.globalAgent.maxSockets = 10;