https://easyteam.fr/galera-cluster-mariadb-principes-installation/
https://developers.redhat.com/blog/2019/02/14/red-hat-sso-high-availability-hybrid-cloud#lessons_from_our_first_deployment
http://people.redhat.com/mlessard/mtl/presentations/mai2020/IntroductionRH-SSO.pdf
https://www.keycloak.org/2018/06/red-hat-single-sign-on-in-keynote-demo.html