In this chapter, we took an in-depth review of garbage collection as a critical Java platform component. Our review included object life cycles, garbage collection algorithms, garbage collection options, and methods related to garbage collection. We looked at upgrades to garbage collection in Java 8, 9, 10, and 11 and looked at a case study to help our understanding of modern garbage collection.

We then turned our focus to the changes to garbage collection with the new Java 9 platform. Our exploration of garbage collection in Java included looks at default garbage collection, depreciated garbage collection combinations, and unified garbage collection logging. We concluded our exploration of garbage collection by looking at a few garbage collection issues that persist, even in the most recent version of Java.

In the next chapter, we will look at how to write performance tests using the Java Microbenchmark Harness (JMH), a Java harness library for writing benchmarks for the JVM.