I have deployed a Bitnami AMI of NodeJS on an AWS micro instance. After starting my node app, everything works fine.
After some time without any activity, the app which is attached to port :3000, seems to shut down. When this happens on refreshing the page my browser gives the message:
Network Error (tcp_error)
A communication error occurred: "Connection refused"
The Web Server may be down, too busy, or experiencing other problems preventing it from responding to requests. You may wish to try again at a later time.
The AWS console shows the instance is still running and the Bitnami build still responds with the standard message on port 80.
As we discussed in comments, the problem was binding the node process to SSH session.
You can use nohup or screen to launch the node process in an instance not bound to session.
I suggest using screen because the function of returning to launched instance is essential for maintenance/updating.
Related: How to run process as background and never die
Related: Command-Line Interface tool to run node as a service