Hey I’m so sorry for the delayed response and perhaps what’s even worse is it was your first post and so I cannot apologize enough for not responding sooner.
To the first question, no there doesn’t appear to be any documentation on how to integrate Ganglia and Open OnDemand.
That said, there’s one integration point that I know of: viewing ganglia graphs in the ‘active jobs’ application. Is that what you are looking for?
I can only speculate as to other integration points or addon apps (apps that don’t ship with the RPM) that may enable other Ganglia graphs that you may be thinking of.
We have one such app - GitHub - OSC/osc-systemstatus - but it’s tailored to OSC so it’s not really a general purpose such that you can just drop in and it would work. You’re welcome to try, but there may be some initial steps to get it to work with your scheduler.