Assessing Contemporary Automated Memory Management in Java – Garbage First, Shenandoah, and Z Garbage Collectors Comparison

Selecting the appropriate automated memory management approach directly impacts application performance and is considered one of the crucial factors in contemporary memory management. In Java, applications are commonly executed within the Java Virtual Machine (JVM), and, for years, it has offered several garbage collection techniques to choose from. The Garbage First (G1) garbage collector (GC) became the standard in 2017 and is currently a widely used garbage collection algorithm. Other GCs evolved in the meantime, such as Shenandoah GC and Z Garbage Collector (ZGC), and they were recently promoted from experimental features to production-ready. Since currently, there are several standard GCs to choose from, we believe that the performance distinctions they manifest should be more thoroughly examined with experimental benchmarks and real-life use cases. Given the importance of GC in automated memory management performance, it is worthwhile to investigate how those GC algorithms handle various memory issues and perform in regards to heap allocation, CPU usage, and time consumption. This paper focuses on the comparative analysis of the default G1 and the Shenandoah and Z GCs, and compares the number of measures in selected application tests from the popular benchmarking suites with all three standard GCs available.