GC Tuning Fundamentals

This section describes three major attributes of garbage collection performance, three fundamental garbage collection tuning principles, and the garbage collection information to collect when tuning a HotSpot VM garbage collector. Understanding the important trade-offs among the attributes, the tuning principles, and what information to collect is crucial to JVM tuning.

The Performance Attributes

• Throughput. A measure of the garbage collector’s ability to allow an application to run at peak performance without regard to the duration of garbage collection pause times or the amount of memory it requires

• Latency. A measure of the garbage collector’s ability to allow an application to experience a minimal amount of, or completely eliminate, pause time or application jitter induced by the garbage collector

• Footprint. A measure of the amount of memory a garbage collector requires to operate efficiently