gistfile1.js

var http = require('http');
var hitCnt = 0;

http.createServer(function (req, res) {
    // myHitCnt is function scope, but the function is
    // a callback and only exists with each req
    var myHitCnt = 0;
    res.writeHead(200, {'Content-Type': 'text/plain'});
    hitCnt++; myHitCnt++;
    console.log('Server 1: ' + hitCnt + ' / my: ' + myHitCnt);
    res.end('Server 1: ' + hitCnt  + ' / my: ' + myHitCnt + '\n');
}).listen(8124, "127.0.0.1");
console.log('Server running at http://127.0.0.1:8124/');

(function () {
    // myVar is function scoped in an anon func this maintains
    // a counter for this server via closure
    var myHitCnt = 0;
    http.createServer(function (req, res) {
        res.writeHead(200, {'Content-Type': 'text/plain'});
        hitCnt++; myHitCnt++;
        console.log('Server 2: ' + hitCnt  + ' / my: ' + myHitCnt);
        res.end('Server 2: ' + hitCnt  + ' / my: ' + myHitCnt + '\n');
    }).listen(8125, "127.0.0.1");
    console.log('Server running at http://127.0.0.1:8125/');
})();

/*

2 calls to :8124 and 3 to :8125

dean@dean:~/Devel$ node node_try.js 
Server running at http://127.0.0.1:8124/
Server running at http://127.0.0.1:8125/
Server 1: 1 / my: 1
Server 1: 2 / my: 1
Server 1: 3 / my: 1
Server 1: 4 / my: 1
Server 2: 5 / my: 1
Server 2: 6 / my: 2
Server 2: 7 / my: 3
Server 2: 8 / my: 4
Server 2: 9 / my: 5
Server 2: 10 / my: 6

*/