What Is Parallel Collector

This section describes the Parallel Collector, which uses the combination of the Parallel Scavenge (PS) Collector of Young generation and the Parallel Old Collector of Tenured generation, so both minor GC and major GC are performed in multiple threads parallelly in a stop-the-world fashion.

What Is Parallel Collector? Parallel Collector is actually a combination of two garbage collectors:

Main features of the Serial Collector:

The Parallel Collector is also called Throughput Collector because it reduces GC time to improve the throughput of the application. It's a good choice for backend applications.

Last update: 2018.

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"

What Is Parallel Collector

 Parallel Collector GC Log Message Format

 "-XX:+PrintGCTaskTimeStamps" - Print GC Threads

 "-XX:ParallelGCThreads=n" - # 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

 "-XX:+PrintAdaptiveSizePolicy" - Minor GC Report

 Adaptive Size Policy Changed Survivor Space

 Adaptive Size Policy Changed Eden Space

 Adaptive Size Policy for Best Latency

 Adaptive Size Policy for Best Throughput

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

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

 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

 Outdated Tutorials

 References

 Full Version in PDF/EPUB