We monitor outgoing smtp and http connections from anything that requires those services. And the best general advice I have is split your alerts into "stuff t

We monitor outgoing smtp and http connections from anything that requires those services. And the best general advice I have is split your alerts into "stuff that I need to know is broken" and "stuff that just helps me diagnose other problems". You don't want to be disturbing your on-call people for stuff that doesn't directly affect your service (or isn't even something you can fix).