This is no big deal at all (as everything is working great so far), but I just saw that the update (from 1.8 to 1.9) consumes much more CPU than before (redis and mariadb). What's the reason exactly?
TL;DR
Update from version 1.8 to 1.9 resulted in a significant increase in CPU usage for redis and mariadb. Developers are curious about the reason behind this change.