I'm curious, and have gone over the documentation but cannot see the wood for the trees now.
Within a setup where remote collectors exist, should these need to be shutdown does the cluster need to be taken offline? Given that node doesn't contain any database elements, I would think not but wondered if there was an official stand point that anyone is aware of?
I dont know of any official documentation on RC specifically but if there is a need to take the cluster offline i would take all offline including the RC. I normally dont reboot them (adding diskspace to the cluster) but bring them offline and online with the cluster is my recommendation. Dont use the cluster management screen for bring nodes offline use the admin UI to bring the full cluster offline.