var zmq = require("zmq");  
var socket = zmq.socket("req");  
var counter = 0;
// Just a helper function for logging to the console with a timestamp.
function logToConsole (message) {  
  console.log("[" + new Date().toLocaleTimeString() + "] " + message);
}
function sendMessage (message) {  
  logToConsole("Sending: " + message);
  socket.send(message);
}
// Add a callback for the event that is invoked when we receive a message.
socket.on("message", function (message) {  
  // Convert the message into a string and log to the console.
  logToConsole("Response: " + message.toString("utf8"));
});
// Begin listening for connections on all IP addresses on port 9998.
socket.bind("tcp://*:9998", function (error) {  
  if (error) {
    logToConsole("Failed to bind socket: " + error.message);
    process.exit(0);
  }
  else {
    logToConsole("Server listening on port 9998");
    // Increment the counter and send the value to the clients every second.
    setInterval(function () { sendMessage(counter++); }, 1000);
  }
});

var zmq = require("zmq");  
var socket = zmq.socket("rep");
// Just a helper function for logging to the console with a timestamp.
function logToConsole (message) {  
  console.log("[" + new Date().toLocaleTimeString() + "] " + message);
}
// Add a callback for the event that is invoked when we receive a message.
socket.on("message", function (message) {  
  // Convert the message into a string and log to the console.
  logToConsole("Received message: " + message.toString("utf8"));
  // Send the message back aa a reply to the server.
  socket.send(message);
});
// Connect to the server instance.
socket.connect('tcp://127.0.0.1:9998');