Deploy the application with the --retrieve option to get the client jar file.
Keep the client jar file on the client machine.
For example:
asadmin deploy --user admin --passwordfile pw.txt --retrieve /my_dir myapp
Run the client jar and the required jar files, specifying the endpoints and InitialContext as -D values.
For example:
java -Dcom.sun.appserv.iiop.endpoints= host1.sun.com:33700,host2.sun.com:33700,host3.sun.com:33700 samples.rmiiiopclient.client.Standalone_Client
To test failover, stop one instance in the cluster and confirm that the application functions normally. You can also have breakpoints (or sleeps) in your client application.
To test load balancing, use multiple clients and see how the load gets distributed among all endpoints.