Here, there is no server running at 127.0.0.2, so the call the http.request at line 12 will emit an error (that should be catched by the domain).

app.js

var domain = require('domain');
var http = require('http');

var respond = function(req, res){
    var httpOptions = {
        host : "127.0.0.2",
        port : 50,
        path : "/",
        method : 'GET'
    };

    var req1 = http.request(httpOptions, function(err1, res1){
        res.writeHead(200);
        res.end('Test !.\n');
    });

    req1.end();
};

http.createServer(function (req, res) {
    var newDomain = domain.create();
    newDomain.add(req);
    newDomain.add(res);

    var domainError = null;
    newDomain.on('dispose', function(){
        console.log("newDomain.on('dispose')");
    });

    newDomain.on('error', function(error){
        domainError = error;
        console.log("newDomain.on('error')");
        try {
            res.writeHead(500);
            res.end('Error occurred, sorry.\n');

            // process.nextTick(function() {
                newDomain.dispose();
            // });
        }
        catch(err){
            console.error('Error sending 500', err, req.url);
            // tried our best.  clean up anything remaining.
            // process.nextTick(function() {
                newDomain.dispose();
            // });
        }
    });

    newDomain.run(function(){
        respond(req, res);
    });
}).listen(1337, '127.0.0.1');

console.log('Server running at http://127.0.0.1:1337/');