As per JBoss Specifications org.jboss.annotation.ejb.Service annotated beans have Singleton behaviour, so only a single instance of the bean exists in the server. Further they can be exposed similar to EJBs with @Remote and @Local which means the calling client will be executing the same instance over multiple calls, so concurrency issues have to be handled manually. I am Still wondering about its behaviour when it is also annotated with @org.jboss.annotation.ejb.Clustered :-) Regards Sarabjit S. Rupaal View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4256908#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...