Understanding Java Garbage Collection and What You Can Do About It

Gil Tene explains how JVM garbage collection mechanisms work, classifying major collectors and discussing trade-offs between responsiveness, throughput, and memory.

From December 2013, Azul Systems CTO Gil Tene. Garbage collection is an integral but often misunderstood part of application behavior on Java platforms. As such, it is important for Java developers to understand how collector mechanisms work. This presentation reviews and classifies the major garbage collectors available in JVMs today. Following an overview of common garbage collection techniques such as generational, parallel, stop-the-world, incremental, and concurrent algorithms, it defines terms and metrics common to all collectors. It also discusses trade-offs in balancing requirements for responsiveness, throughput, space, and available memory and covers some pitfalls, common misconceptions, and garbage collection behavior myths.