I am learning how to set up http fail-over with WildFly. When I follow tutorial under WildFly documentation High Availability Guide - WildFly 8 - Project Documentation Editor it uses Apache httpd instead of Undertow as an example. That confuses me since if I use Apache httpd, then I do not need to use Undertow as web server. Is there any tutorial or instruction on setting up fail-over with WildFly Undertow?