var http = require('http'); var port = parseInt(process.env.PORT, 10) || 8000; var defaultLag = parseInt(process.argv[2], 10) || 100; http.createServer(function(req, res) { res.writeHead(200, { 'content-type': 'text/plain', 'content-length': '2' }); var lag = parseInt(req.url.split("/").pop(), 10) || defaultLag; setTimeout(function() { res.end('ok'); }, lag); }).listen(port, 'localhost');