Parallel Collector - "+XX:+UseParallelGC"

This chapter provides tutorial notes and example codes on the Parallel Collector specified by the '+XX:+UseParallelGC' JVM option. Topics include introduction to Parallel Collector log message format; multiple parallel GC threads; '-XX:+UseAdaptiveSizePolicy' option to dynamically changing 'eden', 'from' and 'to' heap areas.

What Is Parallel Collector

Parallel Collector GC Log Message Format

Log Message Types from Parallel Collector

"--Xlog:gc+task+time=debug" - Print GC Threads

"-XX:ParallelGCThreads" - # of Threads

Parallel Collector Stops Application for Minor/Major GC

PSYoungGen Collector Using Tenuring Age

Parallel Collector Changing NewRatio and SurvivorRatio

Parallel Collector Adaptive Size Policy

Adaptive Size Policy Log Messages

"-Xlog:gc+ergo=trace" - Minor GC Report

Adaptive Size Policy Changed Survivor Space

Adaptive Size Policy Changed Eden Space

Adaptive Size Policy for Best Latency

Parallel Collector Stopped using Young Generation

Adaptive Size Policy for Best Throughput

Conclusions:

Table of Contents

 About This Book

 Heap Memory Area and Size Control

 JVM Garbage Collection Logging

 Introduction of Garbage Collectors

 Serial Collector - "+XX:+UseSerialGC"

Parallel Collector - "+XX:+UseParallelGC"

 Concurrent Mark-Sweep (CMS) Collector - "+XX:+UseConcMarkSweepGC"

 Garbage First (G1) Collector - "+XX:+UseG1GC"

 The Z Garbage Collector (ZGC) - "+XX:+UseZGC"

 Object References and Garbage Collection

 Garbage Collection Performance Test Program

 Performance Tests on Serial Collector

 Performance Tests on Parallel collector

 Performance Tests on Concurrent collector

 Performance Tests on G1 collector

 Garbage Collection Performance Test Summary

 References

 Full Version in PDF/EPUB