Having a cluster built out of Raspberry Pi's is not only fun but also eases your work. As we discussed in our latest article in the series you can use the cluster to compile software or make it gather data from various sources on the Internet. There are many uses for such a thing.
However, after compiling for an hour straight you might get curious as of how your nodes perform. How they work under load, if they're not under-powered or if the CPU temperature is not rising above desired levels. How much memory have you got left in each of the nodes while they're doing tasks. The more nodes you have in your rack, the more information you will have to go through. Luckily there is software out there that can help you visualise such information all at once in various ways.
This is a companion discussion topic for the original entry at https://linuxconfig.org/building-a-raspberry-pi-cluster-part-iv-monitoring