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Azul Zulu Prime Builds of OpenJDK Release Notes

Table of Contents

Looking for Zing? The Azul Zing Virtual Machine is now Azul Zulu Prime Builds of OpenJDK and part of Azul Platform Prime. Learn more.

Release date: May 31, 2021

Changes to the Azul Zulu Prime Builds of OpenJDK (Azul Zulu Prime JVM) made in Azul Platform Prime 21.05.0.0 are summarized on this page.

What’s New

Below is the list of new VM features and updates introduced in Azul Platform Prime 21.05.0.0.

NoZST Heap Elasticity

Azul Platform Prime 21.05.0.0 provides elastic expansion and shrinking of the Java heap. See Recommended Heap Size for details. When heap elasticity is enabled, the Garbage Collector tries to minimize the memory footprint, keeping it between the user-defined range of -Xms and -Xmx. At the same time, the CPU usage of the Garbage Collector is monitored and the memory minimizing goal relaxed in case the CPU usage increases too much. Heap Elasticity is not available when Azul Zulu System Tools (ZST) is installed.

C1 OSR on by Default

Azul Platform Prime 21.05.0.0 makes the OpenJDK C1 OSR the default OSR for the Falcon compiler. The C1 OSR takes much less time and CPU resources to fully optimize your code to steady-state performance.

Removal of License Checks for Stream Builds

  • Stream Builds (previously known as Feature Releases) are now free for use in development, testing, and evaluation. As such, the builds no longer check for an evaluation license.

  • License checks were already removed for Stable Builds (previously known as Update Releases) in the 21.02 Stable Build line. Stable Builds are for customers only.

Performance Improvements

  • Latency improvement for applications with frequent Unsafe.get() and put() calls.

Tool Support

  • Fixed heap dump compatibility issue that prevented opening Azul Zulu Prime head dumps in IntelliJIdea.

  • Enabled jcmd ManagementAgent command option support.