Benchmarkt socket.io

I want to benchmark my socket.io server. I want to test how many parallel connections and messages the server can handle. But my socket.io server crash after some minutes when I start the benchmark with about 200 websockets. I tried to use the cluster module of node.js to share the process to the cores. When I use the cluster module some connections become disconnected after some time. The server that I use for the test is a virtual server on the amazon cloud with this properties: - 7 GB of memory - 20 EC2 Compute Units (8 virtual cores with 2.5 EC2 Compute Units each) - 1690 GB of instance storage - 64-bit platform - I/O Performance: High - API name: c1.xlarge Here is the code of the benchmark-client: ``` var fs = require('fs'); var io = require("socket.io-client"); var host = "http://localhost:3000"; var timeLog = fs.createWriteStream(__dirname+'/public/time.log',{flags:'a',mode:0666, encoding:'encoding'}); var count = 200; var sockets = []; var total = 0; var countTime = 0; var echo = exports; echo.start = function() { fs.writeFile('public/time.log',"",function(err){ if(err) throw err; }); for(var i=0;i<count;i++){ var socket = io.connect(host,{"force new connection":true}); sockets.push(socket); //console.log(i); socket.on("message",function(message){ countTime++; time = new Date().getTime()-message; total+=time; timeLog.write(time+"\n"); socket.send(new Date().getTime()); }); socket.on("disconnect",function(){ console.log("disconnect"); }); } parallelSockets(); var j = 0; } function parallelSockets(){ for(var i = 0 ;i<count;i++){ sockets[i].send(new Date().getTime()); } } ``` And here the code of the socket.io-server: ``` socket.on('message',function(message){ start = new Date().getTime(); socket.send(message); end = new Date().getTime() - start; logfile.write(end+"\n"); }); ``` Is there any security mechanisms on socket.io that blocks so many parallel messages and connections form a client? Can anybody help me?