I have had a recent extremely high CPU usage causing a restriction on my hosting account. The support team sent me a list of some of the causes. The URL below shows only one hour of the error message. Apparently, my site was "calling itself" in their language. There were four hours of high usage, but I didn't see more than what's in this URL report.
I am currently on a shared server and I know that's not sufficient for a multisite. I am in the process of upgrading to a dedicated server.
In the meantime, I'm trying to figure out what is causing these crazy high spikes so I can eliminate them from affecting my new dedicated server.
Thanks for your help.