The main page of Ganglia provides a snapshot for the entire cluster federation, including graphs for CPU and memory utilization, and the number of offline nodes per cluster. The information is displayed for the last past hour by default, but users can change that up to a year using the menu titled "Last" (see below).
By clicking on the cluster title, or any of the figures, users can get node-level information about a cluster (see below for a snapshot for FoRCE). Colors represent the utilization of nodes, for example, red 'hot' nodes are heavily utilized, and blue 'cold' nodes are idle. Offline nodes are also labeled as such.