In this chapter, we will talk about the various subsystems of WildFly as well as their individual tuning possibilities. To get a better understanding of how these subsystems work together, an introduction to the overall history and architecture of WildFly is also given.

An application server is a rather complex piece of software that consists of several enterprise components that must cooperate to fulfill the Java EE specifications. Tuning such a beast can be a daunting task. It's not enough to just understand the Java EE specification and its subspecifications. The real challenge often lies in the understanding of how an application server of choice has been implemented and making practical use of these specifications.

WildFly is, as of 2013, the new name of the historically famous and well renowned JBoss Application Server (JBoss AS). As arguably the most prolific open source application server in the market, JBoss AS made itself famous for being very modular. It...