Method annotated with @Schedule invoked twice in a singletone bean

[freakyprogrammer]

I am running my application on Jboss 7.1.1-final. I have an EJB annotated with @Singleton which has a method which is annoated with @Schedule which I use to push messsages to JMS queue at the scheduled time. But when I deploy to server scheduler is invoked twice on every interval . My Scheduler Class is here

@Singleton
public class SampleSch {

         @EJB
          private MessageProducerService messageProducerService_;


          @Schedule(minute="*/2", hour="*",second="20", persistent=false)
          public void pushMessage() {
   // emailMessage has just to,from,subject and email content which is pushed to JMS Queue   
                    messageProducerService_.pushMsgtoQueue(emailMessage);
          }
}

But Once server started after 2 minutes as scheduled it's invoked twice after two minutes at 20th second.

15:12:20,037 INFO  [myclass] (EJB default - 7) ************ Scheduler started at *************
15:12:20,037 INFO  [myclass] (EJB default - 7) ************ Calling pushMsgtoQueue method to put messages into the Queue *************
15:12:20,093 INFO  myclass] (EJB default - 8) ************ Scheduler started at *************
15:12:20,093 INFO  [myclass] (EJB default - 7) 
push messages into Q at 2013/08/06 15:12:20   -----> First Invocation 


15:12:20,094 INFO  [myclass] (EJB default - 8) ************ Calling pushMsgtoQueue method to put messages into the Queue *************
15:12:20,094 INFO  [stdout] (Thread-6 (HornetQ-client-global-threads--313737904)) Not coming here
15:12:20,095 INFO  [myclass] (Thread-6 (HornetQ-client-global-threads--313737904)) Entering into OnMessage Method
15:12:20,209 INFO  [myclass] (EJB default - 8) 
push messages into Q at 2013/08/06 15:12:20  -----> Second invocation

How Can I resolve this?

[sfcoy]

What does your deployment look like?

Is there any chance that you're using an EAR containing EJB jar and WAR? If so, is there any chance that the WAR got a second copy of the EJB jar in it's WEB-INF/lib directory?

[freakyprogrammer]

Yes. Actually i am doing exactly what you mentioned in your answer by maven multi module structure. My war file has EJB jar which has JMS and Scheduling stuff as a dependency and EAR is the parent of these two files. Does that cause this issue?

[sfcoy]

I'm concerned with the possibility that your WAR file has a copy of the EJB jar in it's WEB-INF/lib directory. EJBs in a WAR get deployed as EJBs in Java EE 6+. ie. Both the EAR and the WAR contain a copy of the EJB jar.

You need to add the EJB jar as a "provided" dependency to the WAR in a conventional multimodule EAR build.

[freakyprogrammer]

Stephen Coy wrote:

I'm concerned with the possibility that your WAR file has a copy of the EJB jar in it's WEB-INF/lib directory. EJBs in a WAR get deployed as EJBs in Java EE 6+. ie. Both the EAR and the WAR contain a copy of the EJB jar.

You need to add the EJB jar as a "provided" dependency to the WAR in a conventional multimodule EAR build.

Thanks stephen, this resolved my issue.