User Guide - Tencent/TencentKona-11 GitHub Wiki

Introduction

  • Free, customized and optimized OpenJDK version
  • Based on OpenJDK 11, compatible with Java standard interfaces, and certified as compatible with the Java SE standard.
  • After the internal testing and use of multiple systems in the data platform department, the stability is highly guaranteed
  • Support new features such as large GC optimization, memory resource cost optimization, and continuous optimization for scenarios such as big data, machine learning, cloud scenarios, and microservices
  • Quarterly synchronization to ensure safe updates

ZGC optimization

  • FEAT(zgc): Concurrent Class Unloading，Reduce pause time by 50%
  • FEAT(zgc): Redesign C2 load barrier，Improve ZGC stability

G1 GC optimizations

  • Backport of JEP 344: Abortable Mixed Collections for G1 GC
  • More information in JEP 344

Print additional information in thread dump

  • Using jstack or jcmd to do thread dump, get more information as below：
    • cpu = ...: the time the thread spent executing on the CPU
    • elapsed = ...: the wall clock time passed since the thread was started.
    • allocated=... : The number of bytes allocated by this thread.
    • defined_classes=... : The number of classes defined by this thread
  • The values 'allocated=' and 'defined_classes=' are only printed if the VM is started with -XX:+PrintExtendedThreadInfo.
  • If the thread dumps are gathered by jcmd, '-e' must be added to the Thread.print command.

ZGC is turned on for trial

-- use -XX:+UnlockExperimentalVMOptions -XX:+UseZGC to enable ZGC