This example demonstrates the deployment of a Service that is wrapped with the SingletonService decorater to be a cluster wide singleton service.
The example is composed of 2 maven projects with a shared parent. The projects are as follows:
service: This project contains the Service and the EJB code to instantiate, start and access the service
client: This project contains a remote ejb client to show the behaviour
pom.xml builds each of the subprojects in the above order and deploys the archive to the server.
The application this project produces is designed to be run on Red Hat JBoss Enterprise Application Platform 6.1 or later.
All you need to build this project is Java 6.0 (Java SDK 1.6) or later, Maven 3.0 or later.
You can copy or link to the Maven configuration information in the README file in the root folder of the quickstarts. For example:
If you have not yet done so, you must Configure Maven before testing the quickstarts.
If you run a non HA profile the singleton service will not start correctly. To run the example one instance must be started, to see the singleton behaviour at minimum two instances should be started.
Start server one : standalone.sh --server-config=standalone-ha.xml -Djboss.node.name=nodeOne Start server two : standalone.sh --server-config=standalone-ha.xml -Djboss.node.name=nodeTwo -Djboss.socket.binding.port-offset=100
NOTE: The following build command assumes you have configured your Maven user settings. If you have not, you must include Maven setting arguments on the command line. See Build and Deploy the Quickstarts for complete instructions and additional options.
Type this command to build and deploy the archive:
mvn clean install jboss-as:deploy
service/target/jboss-cluster-ha-singleton-service.jarto the running instance of the server.
Type this command to deploy the archive to the second server (or more) and replace the port, depending on your settings:
mvn jboss-as:deploy -Djboss-as.port=10099
This will deploy
service/target/jboss-cluster-ha-singleton-service.jar to the running instance of the additional server.
Check whether the application is deployed on each instance. All instances will have a message:
INFO [org.jboss.as.clustering.singleton] (SingletonService lifecycle - 1) JBAS010342: nodeOne/cluster elected as the singleton provider of the jboss.quickstart.ejb.ha.singleton service Only nodeOne (or even one instance) will have a message: INFO [org.jboss.as.clustering.singleton] (SingletonService lifecycle - 1) JBAS010340: This node will now operate as the singleton provider of the jboss.quickstart.ejb.ha.singleton service
Type the following command to start the client:
cd client mvn exec:exec
Check the output. The request to the EJB is running four times and every time it should respond:
# The timer service is active on node with name = NodeOne If you look in the server log files, you will see that each node will process requests
Stop the server
nodeOne. If you look into the server
nodeTwo log file, you will see the message:
JBAS010342: nodeTwo/cluster elected as the singleton provider of ..." This shows that the singleton service was started. The timer will be started here and log a message every 10 seconds.
Repeat step 2. The request is running four times and the message is:
# The timer service is active on node with name = NodeTwo If you look into the server #2 log file you will see that it process all four requests.
When you are finished testing, type this command to undeploy the archive:
mvn jboss-as:undeploy mvn jboss-as:undeploy -Djboss-as.port=10099
You can also start the server and deploy the quickstarts from Eclipse using JBoss tools. For more information, see Use JBoss Developer Studio or Eclipse to Run the Quickstarts
If you want to debug the source code or look at the Javadocs of any library in the project, run either of the following commands to pull them into your local repository. The IDE should then detect them.
mvn dependency:sources mvn dependency:resolve -Dclassifier=javadoc