I would to implement a simple functionality on my server:
I would to know when a my process that it is running on the server is active or no. If this process is not running I would to send an e-mail to administrator.
To implement this functionality I'm thinking to a cron-job scheduled on x hours.
How can I implement this cron-job? I used python server-side.
Is this the better solution?
I'm assuming that your server is *nix, as you're mentioning cronjobs.
You can find bash scripts doing exactly this functionality, if you google it. Here's a bash script which checks for specific services and sends emails if a service is down:
http://bash.cyberciti.biz/monitoring/simple-process-checker-script/
You just need to tweak the _chklist, _sendemail and _email variables to suit your needs