Many people do much of the fancy stuff with system managment products (Tivoli or BMC patrol spring to mind from past experiences). With that they can do centralised monitoring of the server and services and software and automate responses to defined conditions allowing automatic responses with the right thought and alerting callout when exceptions to the rules occur and when things need looking at.

Now all that said, I'm not uptodate on that side of things and even less uptodate on open source alternative, though my quick look at this does indicate that it is a start in the right directon and can only get better. So quick look and glance over gave me a good gut feeling, which is always nice to have.