domain.js

var http = require('http');
var rid = 0;
var uuid;


var server = http.createServer(function(req, res) {
    var domain = require('domain');
    var reqd = domain.create();
    var uuid = require('node-uuid').v1();
    rid += 1;
    console.log('Request ID: ' + rid);

    reqd.uuid = uuid;
    reqd.run(function() {
        setTimeout(function() {
            require('./test1')(uuid);
        }, Math.random() * 5000);
    });

    res.end(uuid + '\n');
});

server.listen(1234);
console.log('Listening on port 1234');

test1.js

var t2 = require('./test2')();

module.exports = function(uuid) {
    process.nextTick(function() {
        require('./test2')(uuid);
    })

    if (uuid !== process.domain.uuid) {
        throw new Error('UUID does not match!');
    }
}

test2.js

module.exports = function(uuid) {
    if (typeof(uuid) !== 'undefined') {
        if (uuid !== process.domain.uuid) {
            throw new Error('UUID does not match!');
        }
    }

    return process.domain.uuid;
}