[Java programming language only]

Java SE considerations

WebSphere® eXtreme Scale requires Java™ SE 6, or Java SE 7. In general, newer versions of Java SE have better functionality and performance.

Supported versions

You can use WebSphere eXtreme Scale with Java SE 6, and Java SE 7. The version that you use must be currently supported by the Java Runtime Environment (JRE) vendor. If you want to use Secure Sockets Layer (SSL), you must use an IBM® Runtime Environment.

IBM Runtime Environment, Java Technology Edition Version 6 , and Version 7 are supported for general use with the product. Version 6 Service Release 9 Fix Pack 2 is a fully supported JRE that is installed as a part of the stand-alone WebSphere eXtreme Scale and WebSphere eXtreme Scale Client installations in the wxs_install_root/java directory and is available to be used by both clients and servers. If you are installing WebSphere eXtreme Scale within WebSphere Application Server, you can use the JRE that is included in the WebSphere Application Server installation. For the web console, you must use IBM Runtime Environment, Java Technology Edition Version 6 Service Release 7 and later service releases only.

WebSphere eXtreme Scale takes advantage of Version 6 , and Version 7 functionality as it becomes available. Generally, newer versions of the Java Development Kit (JDK) and Java SE have better performance and functionality.

For more information, see Supported software.

WebSphere eXtreme Scale features that are dependent on Java SE

Table 1. Features that require Java SE 6, and Java SE 7.

WebSphere eXtreme Scale uses functionality that is introduced in Java SE 6 to provide the following product features.

Feature Supported in Java SE 5 and later service releases
Note: Java SE 5 is not supported in WebSphere eXtreme Scale Version 8.6
Supported in Java SE Version 6 , Version 7 and later service releases
EntityManager API annotations (Optional: You can also use XML files) X X
Java Persistence API (JPA): JPA loader, JPA client loader, and JPA time-based updater X X
Memory-based eviction (uses MemoryPoolMXBean) X X
Instrumentation agents:
  • wxssizeagent.jar: Increases the accuracy of the used bytes map metrics.
  • ogagent.jar: Increases the performance of field-access entities.
X X
Web console for monitoring   X

Upgrading the JDK in WebSphere eXtreme Scale

Common questions about the upgrade process for releases of WebSphere eXtreme Scale in both stand-alone and WebSphere Application Server environments follow: