This page describes how to monitor Garbage Collection for Java applications.

Splunk AppDynamics gathers Garbage Collection metrics and lets you analyze how periodic Garbage Collections affect the performance of your application. It is important to identify the impact of excessive Garbage Collection or memory-caused instability on the application. A typical Java application which runs on the Java Virtual Machine (JVM) creates objects such as strings, files, and arrays of primitives on the heap. The Java Garbage Collection is an automatic memory management process which finds and gets rid of the objects which are no longer used by the application.

The JVM periodically performs Garbage Collection to maximize available memory and the programmer need not explicitly mark the objects to be deleted. Garbage Collection requires a stop-the-world suspension of all application threads. This process affects the performance, especially for applications with large amounts of data, multiple threads, and high transaction rates.

See How to Master Your Java Memory for a review of how generational Garbage Collection works.