Clustering in Java EE and WildFly

WildFly supports clustering for all major Java EE components. For some components, this support is mandated by specification, and for others, WildFly has proprietary support like many other application servers.

In the upcoming sections, we will discuss clustering and related performance tuning as they exist in the different layers of the Java EE stack and relevant subsystems of WildFly.

Clustered EJBs

As we will see, WildFly, like most other application servers, provides support for clustering of the relevant types of EJBs. It is, however, important to remember that clustering of EJBs is still proprietary and not a part of the Java EE specification.

Tip

The @org.jboss.ejb3.annotation.Clustered annotation and its XML counterpart is unique to the WildFly (and JBoss AS and JBoss EAP) application server and not a part of the Java EE APIs.

This type of heterogeneity sometimes makes the work of migrating clustered applications quite complicated. It also makes it hard...