ØMQ - The Guide

// Hello World server
// Binds REP socket to tcp://*:5555
// Expects "Hello" from client, replies with "world"

var zmq = require('zmq');

// socket to talk to clients
var responder = zmq.socket('rep');

responder.on('message', function(request) {
console.log("Received request: [", request.toString(), "]");

// do some 'work'
setTimeout(function() {

// send reply back to client.
responder.send("World");
}, 1000);
});

responder.bind('tcp://*:5555', function(err) {
if (err) {
console.log(err);
} else {
console.log("Listening on 5555…");
}
});

process.on('SIGINT', function() {
responder.close();
});