Java 8 GC Tutorials - Herong's Tutorial Examples - v1.03, by Dr. Herong Yang
Garbage First (G1) Collector - "+XX:+UseG1GC"
This chapter provides tutorial notes and example codes on the Garbage First (G1) Collector specified by the '+XX:+UseG1GC' JVM option. Topics include introduction the G1 Collector; G1 log message format; Stop-The-World behavior of G1 Collector.
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What Is Garbage First (G1) Collector
Garbage First GC Log Message Format
"-XX:ParallelGCThreads=6" - G1 Parallel Threads
Stop-The-World Log Messages of Garbage First Collector
"-XX:+PrintHeapAtGC" - Heap at Each GC
"-XX:G1HeapRegionSize=n" - G1 Region Size
G1 Humongous Allocation - Objects Too Large
"-XX:+PrintTenuringDistribution" - Object Age
"-XX:+MaxTenuringThreshold=0" - Skip G1 Survivors
G1 Major GC Phases
G1 Major GC Copy Phase Failed - Full GC
G1 Major GC Mark Phase Failed - Full GC
Takeaways:
Table of Contents
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"
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