Forgive me if this is a dumb comment to make, as I'm just barely starting to get into monitoring and the statistics knowledge that goes along with it, but adaptive fault detection does tend to scare me a bit. In the event that a problem isn't a spike, and instead gradually builds up over hours/days/weeks, I wouldn't be confident in something picking a dynamic threshold for me. I'd be afraid of it deeming the ever-rising resource usage as normal behavior, if it happens slow enough, and me not being alerted before it's too late (servers becoming unresponsive).
