Like every other Java application, the WildFly application server requires an engine to operate. This engine can interpret and handle Java bytecode. As such, it has been named Java Virtual Machine (JVM).

With every release of Java, a lot of changes and improvements to JVM have been introduced. Over time, it has become increasingly faster and more intelligent in determining how it should configure itself in order to give its best for any particular situation and environment. The result is a highly advanced runtime that has become easier to use but still needs some of our love and understanding from time to time.

So, we need to understand how JVM operates, how to interpret what it tells us, and how to tune it to make it work even more efficiently. In order to properly reach these goals, we will learn a lot more about JVM in this chapter by discussing the following topics: