Service refresh 7

Read about the changes in service refresh 7, and subsequent fix packs.

Skip to Service refresh 7 fix pack 5.

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Skip to Service refresh 7 fix pack 16.

Skip to Service refresh 7 fix pack 20.

Service refresh 7

This release contains IBM and Eclipse OpenJ9 fixes, the most recent Oracle Critical Patch Update (CPU), and the following new features:

  • IBM security features, as listed in Security guide.
  • Other SDK features, as listed in the following sections.
Other SDK features
New operating system and hardware support

The following operating systems are now supported:

  • AIX® 7.3
  • SUSE Linux® Enterprise Server (SLES) 15 SP3
  • Windows 11
  • Windows Server 2022
  • z/OS® 2.5

IBM® Power10 systems are now also supported.

For more details, see Supported environments.

Update to the Java™ launcher on AIX

On AIX operating systems, the Java launcher (java command) and utilities (such as javac, jconsole, jar and others) now set the environment variable MALLOCOPTIONS=multiheap,considersize to improve performance, particularly when the OpenJCEPlus security provider is used. If you start a process from your Java code (for example by using the java.lang.ProcessBuilder or java.lang.Runtime.exec() APIs) that inherits the environment in which your Java code runs, this environment variable is also set for that process.

If you do not want the MALLOCOPTIONS variable set for the new process, either exclude the variable when you start the new process in your Java code, or start the new process then remove the variable. For example, if you are using the java.lang.ProcessBuilder API, you can use the environment() method to return a Map object that lists the environment variables that are in effect. You can then remove the MALLOCOPTIONS environment variable from the Map object before you use the start() method to start the new process. Alternatively, if the new process is a UNIX shell script, you can start the process without modifying the inherited environment, then specify unset MALLOCOPTIONS in the shell script so that the variable is removed after the process starts.

Service refresh 7 fix pack 5

Fix pack 5 contains the latest IBM fixes, the most recent Oracle Critical Patch Update (CPU), and the following new features:

Service refresh 7 fix pack 6

Fix pack 6 includes the latest IBM fixes and the following new OpenJ9 feature:
New SharedClassStatistics API
The following new methods are added to the SharedClassStatistics to provide more data about a shared classes cache: cacheDir(),cacheName(), cachePath(), and numberAttached().
New option -XX:[+|-]EnsureHashed added
This option specifies or ignores classes of objects to be hashed and extended with a hash slot when an object is created or first moved. This option might improve performance for applications that frequently hash objects of a certain type. For more information, see -XX:[+|-]EnsureHashed.

Service refresh 7 fix pack 10

Fix pack 10 contains the latest IBM and Eclipse OpenJ9 fixes, the most recent Oracle Critical Patch Update (CPU), and the following new features:
  • IBM security features, as listed in Security guide.
  • Other SDK features, as listed in the following section.
Other SDK features
New hardware support

Support is added for IBM z16™ hardware. Note that the 31-bit SDK is not supported on Linux on this hardware level.

For a list of supported hardware and software levels, see Supported environments.

Service refresh 7 fix pack 11

Fix pack 11 includes the latest IBM fixes and the following new OpenJ9 feature.
Option -XX:[+/-]ShowHiddenFrames
This diagnostic option specifies whether the generated hidden MethodHandle frames are displayed in a stack trace. For more information, see -XX:[+|-]ShowHiddenFrames.

Service refresh 7 fix pack 15

Fix pack 15 contains the latest IBM fixes, the most recent Oracle Critical Patch Update (CPU), and the following new features:
  • IBM security features, as listed in Security guide.
  • Features from the latest Eclipse OpenJ9 release, as listed in the Version 0.33.1 OpenJ9 user documentation.
  • Other SDK features, as listed in the following section.
Other SDK features
Updated operating system support

Support is added for Red Hat® Enterprise Linux 9.0. For a list of supported hardware and operating systems, see Supported environments.

Service refresh 7 fix pack 16

Fix pack 16 includes the latest IBM fixes, support for Ubuntu 22.04 (see Supported environments for a list of supported operating systems), and the following new OpenJ9 features:
New OpenJ9 option -XX:[+|-]ShowNativeStackSymbols added
Use this option to control whether Java dumps should show the names of functions in native call stacks or not. The available settings are as follows:
  • -XX:-ShowNativeStackSymbols: don't show native stack symbols, even in response to a signal, such as a fault signal.
  • -XX:+ShowNativeStackSymbols=basic: show all the available native stack symbols for a signaled or faulting thread, but only easily acquired native stack symbols for other threads. This is the default setting.
  • -XX:+ShowNativeStackSymbols=all: show all the available native stack symbols for all threads.
Java dumps take longer to produce when the native stack symbols are included. If your Java application has a lot of threads, you might get an incomplete Java dump. You can avoid this situation by reducing the number of native stack symbols in the Java dump or by omitting them altogether. For more information, see -XX:[+|-]ShowNativeStackSymbols.
-XX:+EnsureHashed:java/lang/Class,java/lang/Thread is added to the list of default options in the options.default file
To improve performance, -XX:+EnsureHashed:java/lang/Class,java/lang/Thread setting is added to the list of default options in the options.default file. As a result, when Class and Thread objects are allocated memory on the heap, they are hashed and extended with a slot to store the hash when they are created or first moved as part of garbage collection. For more information about the options.default file, see -Xoptionsfile. For more information about the option -XX:+EnsureHashed, see -XX:[+|-]EnsureHashed.

Service refresh 7 fix pack 20

Fix pack 20 contains the latest IBM fixes, the most recent Oracle Critical Patch Update (CPU), and the following new features:
  • IBM security features, as listed in Security guide.
  • Features from the latest Eclipse OpenJ9 release, as listed in the Version 0.35 OpenJ9 user documentation.
  • Other SDK features, as listed in the following section.
Other SDK features
Updated operating system support

The following operating systems are now supported:

  • Red Hat Enterprise Linux 8.6
  • SUSE Linux Enterprise Server (SLES) 15 SP4

For a list of supported hardware and operating systems, see Supported environments.