This probably sounds on the surface like it'd be an obvious answer to the my question but let me explain a bit further.
I'm looking at the Nodes screen within Marvel (2.3.5) and noticed that next to each metric per node (CPU Usage, JVM Memory etc) there is a downwards facing arrow.
It first lead me to assume that means one of two things.
Either it's to indicate that the value is below some sort of threshold or the value is being trended and is decreasing.
I believe I ruled out the value is decreasing option, since the arrow remained downward pointing even when the value increases significantly, So that leaves me lead to believe it's meant to indicate that the value is within threshold.
Reading through Marvel docs though, I don't see any sort of configurable threshold or explanation however so if anyone can offer the real reason for these arrows and whether any customization to them is available then I'd really appreciate it.