What's new in version 0.20.0

The following new features and notable changes since v 0.19.0 are included in this release:

Features and changes

Binaries and supported environments

OpenJ9 release 0.20.0 supports OpenJDK 8, 11, and 14. Binaries are available from the AdoptOpenJDK community at the following links:

To learn more about support for OpenJ9 releases, including OpenJDK levels and platform support, see Supported environments.

Start of content that applies to Java 11 Limited support for 64-bit Linux on ARM

Limited support is available in this release for the 64-bit ARM (AArch64) architecture. An early access build on OpenJDK 11 is available from the AdoptOpenJDK community. See the OpenJ9 release notes for any known issues that are still being worked on before this platform is fully supported.

-XX:[+|-]ExitOnOutOfMemoryError option behavior update

The -XX:[+|-]ExitOnOutOfMemoryError option is updated to exit only on VM OutOfMemoryErrors instead of both VM and Java™ thrown errors to match the Hotspot option. See -XX:[+|-]ExitOnOutOfMemoryError for more details about this option.

New -XX:[+|-]GlobalLockReservation option added

(AIX and Linux on Power systems only)

Option -XX:[+|-]GlobalLockReservation enables a new optimization targeted towards more efficient handling of locking and unlocking Java objects. See -XX:[+|-]GlobalLockReservation for more details about this option.

Start of content that applies to Java 8 Change to default maximum heap size for Java 8

For consistency with Java 11, the default maximum heap size (-Xmx) is changed to be 25% of the available memory with a maximum of 25 GB. Where there is 2 GB or less of physical memory, the value set is 50% of available memory with a minimum value of 16 MB and a maximum value of 512 MB. If you want to revert to the default setting in earlier releases of OpenJ9, use the -XX:+OriginalJDK8HeapSizeCompatibilityMode option.

Change to jcmd default options

The Java diagnostic command (jcmd) tool no longer requires a filename when used with the Dump.java, Dump.snap, or Dump.system options. See jcmd for more information about the tool.

Full release information

To see a complete list of changes between Eclipse OpenJ9 v 0.19.0 and v 0.20.0 releases, see the Release notes.