Performance Tests on Parallel collector

Java GC Tutorials - Herong's Tutorial Examples

∟Performance Tests on Parallel collector

This chapter provides tutorial notes and example codes on performance impact of Parallel collector, Topics include heap footprint; heap size impact; running Young GC only, running more Old GC.

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Parallel GC Footprint - Free Heap 10%

Heap Size Impact on Parallel GC

Parallel Young GC Not Removing Dead Objects

Performance of Parallel Young GC

Performance of Parallel Full GC

"-XX:MaxTenuringThreshold=0" - Bad for Parallel GC

Tiny Survivor Spaces Are Bad for Parallel GC

Thread Count Impact on Parallel GC

AFFINITY=n - CPU Processors and Parallel GC

Best Parallel GC Configuration

Performance Summary of Parallel Collector

Takeaways:

The Parallel collector requires about 10% free heap space to perform garbage collections.
More free heap space will increase application throughput performance.
Parallel Young GC seems to be more efficient than Old GC.
Forcing the Young GC to "Always Tenure" results poor performance.
Giving enough Young generation space to use Young GC only results the best performance.
Number of GC threads should match the number of CPU processors to get the best performance.

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

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