I used to run a m3.medium instance with Xenforo and Wordpress (without any integration) that floats between 30-50% CPU Utilization..
Last week a got an alert that my instance hit 100%, and since than the CPU is always nearly the maximum capacity, resulting in a very slow navigation around the site.
My board has 400k post and 10k users, with avarege of 50 (from analytics) simultaneosly online.
Given that I had no significant increase in traffic in the period, what would be the solution to this? Moving to a larger instance certainly would solve this, but I wonder if there is something wrong...