Chapter 1. Introduction to the xPaaS EAP Image
1.1. What is JBoss Enterprise Application Platform (EAP)?
Red Hat JBoss Enterprise Application Platform 7.0 (JBoss EAP 7) is an application server that works as a middleware platform, is built on open standards, and is compliant with the Java EE 7 specification.
It is based on Wildfly 10, and provides preconfigured options for features such as high-availability clustering, messaging, and distributed caching.
With JBoss EAP you can develop, deploy, and run applications using the various APIs and services that JBoss EAP provides. JBoss EAP includes a modular structure that allows you to enable services only when required, which results in improved startup speed. The web-based management console and management command line interface (CLI) make editing XML configuration files unnecessary and add the ability to script and automate tasks. In addition, JBoss EAP includes APIs and development frameworks for quickly developing secure and scalable Java EE applications. JBoss EAP 7 is a certified implementation of the Java EE 7 full and web profile specifications.
1.2. How Does JBoss EAP Work on OpenShift?
Red Hat offers a containerized xPaaS image for the Red Hat JBoss Enterprise Application Platform (JBoss EAP) that is designed for use with OpenShift. Using this image, developers can quickly and easily build, scale, and test applications that are deployed across hybrid environments.
1.3. Comparison: EAP and xPaaS EAP Image
There are some notable differences when comparing the JBoss EAP product with the available JBoss EAP xPaaS image. The following table describes these differences and notes which features are included or supported in the current version of the EAP xPaaS image.
Table 1.1. Differences between EAP and EAP xPaaS Image
| Feature | Status | Description |
|---|---|---|
EAP Management Console | Not included | The EAP Management Console is not included in this release of EAP xPaaS image. |
Domain mode | Not supported | Although domain mode is not supported, creation and distribution of applications are managed in the containers on OpenShift. |
Default root page | Disabled | The default root page is disabled, but you can deploy your own application to the root context as ROOT.war. |
Remote messaging | Supported | A-MQ for inter-pod and remote messaging is supported. HornetQ is only supported for intra-pod messaging and only enabled when A-MQ is absent. The EAP 7 xPaaS image includes Artemis as a replacement for HornetQ. |
1.4. Comparison: EAP 6.4 and xPaaS EAP 7.0 Image
Red Hat offers two xPaaS EAP images for use with OpenShift. The first is based on JBoss EAP 6.4 and the second is based on JBoss EAP 7. There are several differences between the two images:
JBoss Web is replaced by Undertow
- The xPaaS JBoss EAP 6.4 image uses JBoss Web.
- The xPaas JBoss EAP 7 image uses Undertow instead of JBoss Web. This change only affects users implementing custom JBoss Web Valves in their applications. Affected users must refer to the Red Hat JBoss EAP 7 documentation for details about migrating JBoss EAP Web Valve handlers.
HornetQ is replaced by Artemis
- The EAP 6.4 image only uses HornetQ for intra-pod messaging when A-MQ is absent.
- The EAP 7 image uses Artemis instead of HornetQ. This change resulted in renaming the
HORNETQ_QUEUESandHORNETQ_TOPICSenvironment variables toMQ_QUEUESandMQ_TOPICSrespectively. For complete instructions to deal with migrating applications from JBoss EAP 6.4 to 7, see the JBoss EAP 7 Migration Guide.
1.5. Version Compatibility and Support
The xPaaS images for OpenShift are updated frequently. Therefore, it is important to understand which versions of the xPaaS images are compatible with which versions of OpenShift. Not all images are compatible with all OpenShift 3.x versions. Visit the Red Hat Customer Portal and see the OpenShift and Atomic Platform Tested Integrations page for more information on version compatibility and support.