Understanding Concurrent Mark Sweep Garbage Collector Logs

Concurrent Mark Sweep (CMS) is a type of Garbage Collector (GC) available in the Java Virtual Machine (JVM) of the Java 2 SDK. This document explains the traces generated by JVM when run with certain diagnostic flags, specifically the logs generated with VM option -XX:+PrintGCDetails for this collector.

Java technology-based applications can be instructed to run with CMS for the old generation by specifying -XX:UseConcMarkSweepGC. However, starting with JDK version 1.5, on server-class machines, VM automatically chooses CMS as the collector for the old generation. 继续阅读 →