Node.js + socket.IO决定每个实例的最大客户端数量

Question

我被要求粗略计算一个套接字可以连接多少个连接。在大型EC2实例(16Gb Ram, 4 Core Xeon)上执行io实例句柄。

我更新了简单套接字的示例。io基准。

Serever:

var io = require('socket.io').listen(80);
var exec = require('child_process').exec; 
io.configure(function() {
  io.set('log level', 1);
  var transport = process.argv.length >= 2 ? process.argv[2] : null;
  if (transport) {
    io.set('transports', [transport]);
  }
});
var payload = "Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item " +
"Payload: Payload line item ";
var users = 0;
function roundNumber(num, precision) {
  return parseFloat(Math.round(num * Math.pow(10, precision)) / Math.pow(10, precision));
}
setInterval(function() { 
  io.sockets.emit("message", payload);
  console.log("Users: " + users);
}, 3000);
io.sockets.on('connection', function(socket) {
  users++;  
  socket.on('disconnect', function() {
    users--;
  })
});

客户

var io = require('socket.io-client');
var message = "o bispo de constantinopla nao quer se desconstantinopolizar";
var receivedMessages = 0;
function user(shouldBroadcast, host, port) {
  var socket = io.connect('http://' + host + ':' + port, {
    'force new connection': true
  });  
  socket.on("message", function(){    
    receivedMessages += 1;
  })
};
var argvIndex = 2;
var users = parseInt(process.argv[argvIndex++]);
var rampUpTime = parseInt(process.argv[argvIndex++]) * 1000; // in seconds
var newUserTimeout = rampUpTime / users;
var shouldBroadcast = process.argv[argvIndex++] === 'broadcast' ? true : false;
var host = process.argv[argvIndex++] ? process.argv[argvIndex - 1]  : 'localhost';
var port = process.argv[argvIndex++] ? process.argv[argvIndex - 1]  : '3000';
for(var i=0; i<users; i++) {
  setTimeout(function() { user(shouldBroadcast, host, port); }, i * newUserTimeout);
};
setInterval(function() {
 console.log("Messages received: " + receivedMessages);
 receivedMessages = 0;
}, 3000);

我运行了这个示例，客户机启动在中型实例上，服务器启动在大型实例上。我得到的结果是每3秒接收到大约4500条消息。

但是网络、cpu和ram的使用率在2-10%的范围内。

是否可以增加服务的连接数?

Server OS为Windows Server 2008 R2

Answer 1

很可能是客户端和服务器之间的延迟，也可能是客户端传出连接数量的限制，以及服务器上传入连接的操作系统限制。请注意，windows有比其他操作系统更低的限制。

你也会期望CPU, RAM和带宽的使用是低的，因为你正在做的操作既不是计算，RAM或带宽重。

请将ApacheBench视为测试服务器的一种方式，而不是编写客户端，这可能是也可能不是最佳实现:https://en.wikipedia.org/wiki/ApacheBench

在任何情况下，使用更多来自不同网络的客户端计算机，这样您就可以将本地交换机或路由器作为瓶颈