In the previous chapter, we illustrated the basic concepts of how to cluster web applications. However, this is only part of the story. To further improve availability, we need to look at how to load-balance your WildFly servers.

Load balancing is the distribution of incoming traffic between servers that host the same application content. Load balancing improves application availability by ensuring that any single server does not take too much load, and that the application remains available should a single server fail.

Historically, the JBoss AS has inherited the load-balancing libraries from Tomcat, which was part of the application server's web module. The web module used mod_jk (an Apache module) to connect Tomcat to a web server, such as Apache. For those of you who are unfamiliar with Tomcat and Apache, Tomcat (also known as Apache Tomcat) is an open source servlet container, while Apache (also known as Apache2 or Apache HTTPD) is an HTTP web...