Minecraft Docker OpenJ9 ShenandoahGC: Ultra-low lag with Shenandoah GC

docker-compose.yml

version: '3'

services:

  minecraft-server:
    ports:
      - "25565:25565"

    environment:
      EULA: "TRUE"
      # # OLD Safer opts                                                                                                                                                                                                                                                                                                                                                                  
      # JVM_XX_OPTS: "-server -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+CMSIncrementalPacing -XX:ParallelGCThreads=2 -XX:+AggressiveOpts"                                                                                                                                                                                                                                             

      # Matt's wacky new opts:                                                                                                                                                                                                                                                                                                                                                            
      # JVM_XX_OPTS: "-server -Xms4G -Xmx4G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:GCTimeRatio=99 -XX:MaxTenuringThreshold=4 -XX:G1NewSizePercent=60 -XX:InitiatingHeapOccupancyPercent=90 -XX:G1MixedGCLiveThresholdPercent=95 -XX:G1ReservePercent=5 -XX:G1MixedGCCountTarget=8 -XX:G1OldCSetRegionThresholdPercent=5 -XX:MaxGCPauseMillis=25 -XX:G1HeapRegionSize=32M -XX:G1ConcRefinementThreads=4 -XX:ParallelGCThreads=8 -XX:G1HeapWastePercent=70 -XX:+ParallelRefProcEnabled -XX:+AlwaysPreTouch -XX:+DisableExplicitGC -XX:+AggressiveOpts"                                                                                                                                                                                                                    
      # Better shenandoahGC:                                                                                                                                                                                                                                                                                                                                                              
      JVM_XX_OPTS: "-server -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC"

      MEMORY: "3G"

    image: itzg/minecraft-server:openj9

    container_name: mc

    tty: true
    stdin_open: true
    restart: always

    volumes:
      - /etc/localtime:/etc/localtime:ro
      - /minecraft:/data