What's the point of J2EE or an application server? You can get functionality such as templates, management, monitoring, persistence through other means as well.
Kubernetes, Istio, Prometheus, All the Hashicorp stuff, hyperledger, traefik , kong you name it.
EDIT: I see from the docs http://docs.wildfly.org/14/High_Availability_Guide.html that you need to configure an Infinispan cluster, what looks like a non-trivial operation.