What is it?
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
The root pom.xml builds each of the subprojects in the above order and deploys the archive to the server.
System requirements
All you need to build this project is Java 6.0 (Java SDK 1.6) or better, Maven 3.0 or better.
The application this project produces is designed to be run on JBoss Enterprise Application Platform 6 or JBoss AS 7.
Configure Maven
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.
Start JBoss Enterprise Application Platform 6 or JBoss AS 7 with a HA profile
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
Build and Deploy the Quickstart
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.
- Make sure you have started the JBoss Server as described above.
- Open a command line and navigate to the root directory of this quickstart.
-
Type this command to build and deploy the archive:
mvn clean install jboss-as:deploy This will deploy
service/target/jboss-as-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-as-cluster-ha-singleton-service.jarto 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
The timer on the started node will log a message every 10sec.
Check the timer
- Open a command line and navigate to the root directory of this quickstart.
-
Type this 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 answer # The timer service is active on node with name = NodeOne If you look into the servers logfiles you will see that each node will process requests - Stop the server nodeOne
If you look into the server nodeTwo logfile you will see the message "JBAS010342: nodeTwo/cluster elected as the singleton provider of ..." that shows that the singleton service was started here The timer will be started here and log a message every 10sec. - 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 logfile you will see that it process all four requests.
Undeploy the Archive
- Make sure you have started the JBoss Server as described above.
- Open a command line and navigate to the root directory of this quickstart.
-
When you are finished testing, type this command to undeploy the archive:
mvn jboss-as:undeploy mvn jboss-as:undeploy -Djboss-as.port=10099
Run the Quickstart in JBoss Developer Studio or Eclipse
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
Debug the Application
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
Share the Knowledge
Find this guide useful?
Feedback
Find a bug in the guide? Something missing? You can fix it by forking the repository, making the correction and sending a pull request. If you're just plain stuck, feel free to ask a question in the user discussion forum.
Recent Changelog
- Feb 13, 2013: Apply fixes made to eap for bugs 910704, 910732, 910882 Sande Gilda
- Feb 12, 2013: Add quickstart source repository of record to the readme files Sande Gilda
- Jan 24, 2013: Use new property names for the maven plugin James R. Perkins
- Sep 11, 2012: Add target product (https://issues.jboss.org/browse/jdf-108) Sande Gilda
- Jul 23, 2012: Add metadata for cluster-ha-singleton and inter-app Pete Muir
- Jul 20, 2012: Align/simplify naming Pete Muir