I want to hear your opinion about program life monitoring.

This is the scenario. You have a simple program which **normally** works, that means that it's well written, exception are handled and so on.

How will you operate if you want to ensure that this program works **FOREVER**?

No external tools like crontab are available, but any overhead can be added.

Using another program that continuously "pings" the main program? Touching a file and check with another program for the file modification?

And how do you assure that this second program always works?

So, come on, tell me which are your opinion or best practice in this context!

As footnote, I've to write this program in Python, but it's a general purpose question!