Garbage First Garbage Collector

Explore the Garbage First (G1) Garbage Collector, set to become the default in Java 9, in this comprehensive 47-minute conference talk by Monica Beckwith at Devoxx. Dive into G1 GC's features, including incremental compaction, stop-the-world collections, and concurrent marking phase. Learn from Beckwith's extensive experience in optimizing G1 GC performance to help customers achieve their SLAs. Gain insights into traditional Java heap, G1 GC heap regions, humongous objects, collection sets, remembered sets, and pause histograms. Understand the stages of concurrent marking, class unloading, and strategies for taming mixed collections. Discover techniques for adjusting mixed collections, eliminating expensive old regions, and avoiding evacuation failures. Analyze G1 heap waste percentage, mixed GC liveness threshold, and learn to plot allocation and promotion rates for optimal performance.

Intro
Traditional Java Heap
Garbage First GC - Heap Regions
G1 GC Heap Regions
Humongous Objects
Collection Set
Remembered Sets
G1 GC - Pause Histogram
Initiating Heap Occupancy
Stages of Concurrent Marking
Class Unloading with Concurrent Mark
The Garbage First Collector
Why Tame Mixed Collections?
What Can We Do?
Adjusting Each Mixed Collection
Eliminating Expensive Old Regions From Mixed Collections
Major Contributor?
So, What Did We Observe?
G1 Heap Waste Percentage
G1 Mixed GC (Region) Liveness Threshold
Avoiding Evacuation Failures
Plot Allocation & Promotion Rates