Kevin Schroeder has a post to his site sharing some helpful tips for monitoring Magento jobs and crons to help provide a bit more information about the job and its current state.

About a month ago a client of mine was lamenting the fact that they didn’t have insight into what was going on with their cron jobs. So I did what any idiot would do and built out a service that does just that. It works with any Magento version, 1 or 2, system crons, and you can use an API to integrate it with your own system with a very minimal amount of work. I call it the 10n Job Health Vault. With Magento 1 or 2 you can have it set up and running in under 5 minutes (minus DI compilation time, of course).

The tool tracks the execution of the job and notifies you if something's wrong and it hasn't finished. This also means it can track the execution time and report back if it's slower than usual. You can find out more information about this Magento monitoring tool on its website.