advise in setting up redis database server


I have 21 jails all running their own www/hiawatha webserver and version of lang/php70 but all sharing 1 common databases/mariadb101-server database (also in a jail).
I am now thinking of installing databases/redis and I wondered if anyone could provide me some advises..
99% of my website are wordpress site.. So my option is either to set redis in every jail and configure Redis as a Cache application as per this article or set a separate jail as redis server to connect all the other jail as per this video and then use a plugin to connect all the web application to it..

Could someone please advise on the best aproche?

I never got to implement this project..
But from all the advice I got from various places settings up 1 redis per jails was best solution.