Realtime interaction of two server side Node.js apps
<p>I know a bit about <code>socket.io</code> which enables realtime bi-directional communication between client and server but I want to run two apps on the server for this purpose. I mean I don't want a user to have access over the running port from outside. (A realtime communication between two apps only)</p>

<p>The case is: one app should be running always and one app is executed on specific time intervals.</p>

<p>I'm not sure if I expressed my thoughts as I should, but I appreciate your guides if you got what I suppose to do. I don't know how I can achieve this hence the question is exactly "how"? (Tips needed)</p>