Having erratic performance issues after upgrade today. Admin center is slow loading/saving new pages. Actual site performance is very erratic, sometimes loads in a a second or two (normal) sometimes takes 10 seconds. Same is true when drilling down in a thread, sometimes very quick, sometimes not. Checked the DB and it looks fines, no errors and restarted MySQL. Cleared the system caches. No differences. Upgrade installer ran with no errors.
I have contacted my ISP also but they didn't see anything out of the ordinary. They did open a service ticket to check in more detail.
Ideas, suggestions?