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What's new in version 0.46.0

The following new features and notable changes since version 0.45.0 are included in this release:

Features and changes

Binaries and supported environments

Eclipse OpenJ9™ release 0.46.0 supports OpenJDK 8, 11, 17, 21, and 22.

Support for running OpenJ9 with all versions of OpenJDK on CentOS 6, CentOS 7, Red Hat Enterprise Linux (RHEL) 6, and RHEL 7 is removed.

RHEL 8.6 and 9.0 are out of support. RHEL 8.8 is the new minimum operating system level.

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

MD5 message digest algorithm support for OpenSSL

OpenSSL native cryptographic support is added for the MD5 message digest algorithm, providing improved cryptographic performance. OpenSSL support is enabled by default. If you want to turn off support for the MD5 message digest algorithm, set the -Djdk.nativedigest system property to false.

Support added for the com.sun.management.ThreadMXBean.getTotalThreadAllocatedBytes() API

With this release, the OpenJ9 VM implementation supports measurement of the total memory allocation for all threads (com.sun.management.ThreadMXBean.getTotalThreadAllocatedBytes() API).

The getTotalThreadAllocatedBytes() method now returns the total thread allocated bytes instead of -1.

The JITServer AOT caching feature enabled by default at the JITServer server

-XX:+JITServerUseAOTCache is the default setting at the JITServer server now. That means that you don't have to specify the -XX:+JITServerUseAOTCache option at the server to enable the JITServer AOT caching feature.

Although this option is by default enabled at the server, it is still disabled for the JITServer clients. The clients that want to use the JITServer AOT caching, must still specify the -XX:+JITServerUseAOTCache option on the command line. Also, now the clients don't have to enable the shared classes cache feature to use the -XX:+JITServerUseAOTCache option.

For more information, see -XX:[+|-]JITServerUseAOTCache.

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

By default, the extended Hot Code Replace (HCR) capability in the VM is disabled for all OpenJDK versions. You can enable or disable the HCR capability by using the -XX:[+|-]EnableExtendedHCR option.

The extended HCR feature is deprecated in this release and will be removed in a future release. From OpenJDK 25 onwards, extended HCR will not be supported. Following that, the extended HCR support will be removed from other earlier OpenJDK versions also.

Known problems and full release information

To see known problems and a complete list of changes between Eclipse OpenJ9 v0.45.0 and v0.46.0 releases, see the Release notes.