WebLogic clustered singleton service

Question

Hi there, guys!

I am currently trying to implement a singleton service over WebLogic, using a WebLogic cluster. I've read some literature about clustered singleton services on WebLogic, and I know I have to implement weblogic.cluster.singleton.SingletonService interface on the object I want to clusterize as a singleton.

import weblogic.cluster.singleton.SingletonService;

public class SingletonOrchestrator implements SingletonService {

    public void activate() {
        System.out.println(":: activate CALLED FOR SingletonOrchestrator");
    }
    public void deactivate() {
        System.out.println(":: deactivate CALLED FOR SingletonOrchestrator");
    }

    (...)

}

I'm able to deploy this as an application on WebLogic, although it doesn't seem to invoke activate() and deactivate() methods after deployment. I don't know what else I have to do in order to have this working as a singleton service in my WebLogic cluster.

Does anybody have experience with this? Can anyone provide a working example and explain to me what else I have to do?

Answer 1

The installation steps are detailed in Automatic Migration of User-Defined Singleton Services:

• Implement the Singleton Service Interface

• Deploy it and Configuring the Migration Behavior

  • Package and deploy the singleton service within an application (in weblogic-application.xml).
    ~ or ~
  • Deploy the singleton service as a standalone service within WebLogic Server (in config.xml).
  • Optionally, configure the migration behavior of the singleton service.

Also have a look at Configure a Singleton Service in the Administration Console Online Help.