JBoss EAP HA Singleton Web Applications

This is another entry about JBoss EAP, configured with HA, but now we’re adding singleton web applications into the mix.

The jboss-developer community has a project on Github that has a ton of ready-to-go examples. See jboss-eap-quickstarts to see all their different quickstarts.

I’m basing my work off of the ha-single-deployment project, in the 7.2.0.GA branch.

Running mvn clean package produces a completely deployable jar file, but we’re interested in creating a WAR file. Luckily, it only takes a two modifications.

Steps

Modify pom.xml

You’ll need to change the packaging format from EJB to WAR.

<artifactId>ha-singleton-deployment</artifactId>
<!--packaging>ejb</packaging-->     <!-- original packaging -->
<packaging>war</packaging>          <!-- new packaging -->
<name>Quickstart: HA Singleton Deployment</name>

Move singleton-deployment.xml

The sample project already has the singleton-deployment.xml file, so we just need to move it so that it’s at the top level of the generated WAR. Maven’s convention is to look at the webapp folder, so just create that folder and move the META-INF folder there.

src/main
├── java
│   └── org
│       └── jboss
│           └── as
│               └── quickstarts
│                   └── ha
│                       └── singleton
│                           └── SingletonTimer.java
├── resources
└── webapp
    └── META-INF
        └── singleton-deployment.xml

That’s it! There are options for how you control the singleton deployment, but that’s a topic for another day.