Understanding Low Latency JVM GCs

Explore the world of low latency JVM Garbage Collectors in this 50-minute Devoxx conference talk. Dive deep into the internals of emerging GCs like Shenandoah, ZGC, and Azul C4. Learn about Concurrent Marking, tri-color marking, C4's Load Value Barrier, Shenandoah's Brooks Pointers, and ZGC's multi-mapping. Understand the intricacies of these advanced GC algorithms, including their phases, notable changes, and underlying mechanisms. Discover how to choose the right low latency GC for your needs. Benefit from the expertise of Jean Philippe Bempel, a developer passionate about performance, runtimes, and Mechanical Sympathy, with over 8 years of experience in low latency trading systems.

Introduction
Agenda
Concurrent Marking
Issues with Concurrent Marking
Concurrent Marking Example
Snapshot Algorithm
Shenandoah
Brooks Pointer
Evacuation
Pseudocode
Phases
Notable Changes
C4 Explanation
LBB Explanation
Virtual Memory vs Physical Memory
Pages Faces
Mark Phase
Relocation Phase
Fixing References
Why C4
CDC
Masking
Which algorithm to use
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