Reading java -version | IBM Semeru Runtime Open Edition

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This all started with the simple command

java -version

IBM Semeru Runtime Open Edition 11.0.23.0 (build 11.0.23+9)
Eclipse OpenJ9 VM 11.0.23.0 (build openj9-0.44.0, JRE 11 Windows Server 2022 amd64-64-Bit Compressed References 20240523_914 (JIT enabled, AOT enabled)
OpenJ9   - b0699311c7
OMR      - 254af5a04
JCL      - 3d1045c3ea based on jdk-11.0.23+9)

1. IBM Semeru Runtime Open Edition 11.0.23.0:

• This is the version of the IBM Semeru Runtime, which is based on the OpenJDK project. The version number 11.0.23.0 indicates it is for Java 11.

2. Eclipse OpenJ9 VM 11.0.23.0:

• OpenJ9 is an open-source Java virtual machine (JVM) developed by the Eclipse Foundation. It is designed to be efficient and is often used in enterprise environments due to its quicker startup time and less memory footprint.
• The version number 11.0.23.0 matches the JDK version, and openj9-0.44.0 indicates the specific version of the OpenJ9 VM.

3. Build details:

• Build number: 11.0.23+9 indicates the specific build of the JDK.
• JRE 11: This confirms that the runtime environment is Java Runtime Environment version 11.
• Windows Server 2022 amd64–64-Bit Compressed References: Specifies the operating system and architecture. In this case, it is Windows Server 2022 with a 64-bit AMD architecture, using compressed references to optimize memory usage.
• Build date: 20240523_914 suggests the build was completed on May 23, 2024, with build identifier 914.

4. JIT enabled, AOT enabled:

• JIT (Just-In-Time compilation): This is enabled, which means the VM compiles code at runtime for improved performance.
• AOT (Ahead-Of-Time compilation): This is also enabled, meaning some code can be compiled before runtime, further optimizing performance.

5. Source Control Identifiers:

• OpenJ9: b0699311c7
• OMR: 254af5a04
• JCL: 3d1045c3ea based on jdk-11.0.23+9

These are the specific commits or changesets from the source repositories for OpenJ9, OMR (Open Managed Runtime, a component of OpenJ9), and JCL (Java Class Library).

To know about IBM Semeru Runtime Open Edition vs IBM Semeru Runtime Certified Edition — https://www.ibm.com/support/pages/semeru-runtimes-getting-started

More about Eclipse OpenJ9 — https://github.com/eclipse-openj9/openj9

More on this from IBM Blogs — https://developer.ibm.com/blogs/openjdk-with-eclipse-openj9-no-worries-just-improvements/

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