CA Identity Manager once deployed on a cluster, should continue processing events/tasks even after individual cluster members are shut down or killed.
The intricacies of the wide variety of parameters involved to ensure the above as well as the meaning behind this type of setup will be outlined in this document.
Release: Identity Manager
This is a suggested approach to failover - there can be numerous different patterns to building out your JBoss/WildFly cluster and those details can be understood from Jboss/WildFly documentation.