Reverse TCP proxy that can start and stop the proxied application

Question

I'm looking for a reverse TCP proxy (or similar) that is capable of starting and stopping the proxied application as needed.

Something like this:

1. The proxy listens on a specified port (nothing special here), but the application is not running.
2. If a client connects to the port, the proxy accepts the connection and starts the application (unless it is already running).
3. Once the application is started, the proxy passes the request to the application and serves its response (usual proxy behavior).
4. If the (last) client disconnects, the proxy stops the application (possibly after some delay in case of a promptly reconnect).

Reason for this is that the application is very resource intensive and it is only accessed occasionally.

The proxy should therefore be lightweight. My server runs CentOS.

Answer 1

It is not a reverse proxy, but inetd works this way. It listens on a port, starts the service on client access, and stops it when the port is closed. It is different from a reverse proxy because it communicates with the service over standard input and standard output, rather than a TCP connection, but many services support this mode of operation.