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1. Introduction
    1.1. Project/Component Working Name:
	Generic JMS Resource Adapter Integration

    1.2. Name(s) and e-mail address of Document Author(s)/Supplier:
	Ramesh Parthasarathy [rampsarathy@dev.java.net, rameshp@sun.com]
			
    1.3. Date of This Document:
	August 17 2006

2. Project Summary
    2.1. Project Description:
       To promote glassfish integration with other JMS providers, generic jms
       resource adapter version 1.7 (https://genericjmsra.dev.java.net) will be
       integrated with  the application server . Through this integration 
       developers will be able to take advantage of some feature enhancements 
       like reliable redelivery, load balancing for topic destinations in a
       cluster and monitoring. 

2.2. Risks and Assumptions:

3. Problem Summary
    3.1. Problem Area:
        The current version of generic jms ra (1.5) that is bundled with glassfish 
        does not support the following 
        a. Transaction recovery when redelivery is enabled. 
        b. Load balancing of messages from topic destinations to Message driven 
        bean endpoints in an application server cluster.
        c. Monitoring the resource pool parameters.

    3.2. Justification:
	The above features are required in an enterprise system.

4. Technical Description:
     4.1. Details:
	4.1.1 Reliable message redelivery :
        Redelivery is a feature in Generic JMS RA that can be used to resend
        the message to an MDB ( or any listener implementation) if there was
        an exception during the first send attempt. If the first invocation
        of the MDB's listener method throws an exception then the RA tries
        to redeliver it N ( number of redelivery attempts configured using the
        activation config property RedeliveryAttempts in inbound endpoint)
        times at an interval ( configured using activation property
        RedeliveryInterval). If redelivery is unsuccessful even after the 
        attempts are exhausted the RA tries to send the message to a Dead
	 Message Destination ( a JMS destination configured in the activation
        config). In 1.5 that is bundled currently, redelivery was un-reliable 
        because redelivered messages could not be recovered during 
        transaction recovery. 
        
        4.1.2 Load balancing topic destinations :
        A message driven bean that is deployed on an application server 
        cluster is deployed on all instances of the cluster. If the bean is 
        listening to a JMS topic destination for messages then there are N 
        ( N is the number of instances in the cluster) separate subscribers 
        for the same topic. This causes the same message being received and 
        processed by all N instances in the cluster. This results in duplicay 
        and also in-efficiency, which are some of the undesirable
        characteristics of reliable and highly available enterprise systems. 
        In 1.7, a message would be received and processed by one and only one
        instance of the application in a cluster.
				
        4.1.3	Monitoring :
        It would be useful to add JMX monitoring to Generic JMS RA. Attributes 
        related to the pool usage and configuration information will be exposed 
        through JMX MBeans.


     4.2. Bug/RFE Number(s):
	https://genericjmsra.dev.java.net/issues/show_bug.cgi?id=24
	https://genericjmsra.dev.java.net/issues/show_bug.cgi?id=27
	https://genericjmsra.dev.java.net/issues/show_bug.cgi?id=26

     4.3. In Scope:


     4.4. Out of Scope:

     4.5. Interfaces:

        4.5.1 Exported Interfaces
       		JMX interface : TBD            
        4.5.2 Imported interfaces
       		None
        4.5.3 Other interfaces (Optional)
       		None
     4.6. Doc Impact:
		None
     4.7. Admin/Config Impact:
		None
     4.8. HA Impact:	
		None

     4.9. I18N/L10N Impact:
		None
     4.10. Packaging & Delivery:
		None
     4.11. Security Impact:
		None
     4.12. Compatibility Impact
		None
		
     4.13. Dependencies:
           Testing:
		SQE has to test the RA with SunMQ and WebSphere MQ. Testing
           involves creation of new test cases for features added as well
           as executing the current set of tests.

5. Reference Documents:
	https://genericjmsra.dev.java.net/docs/redelivery/redelivery.html

6. Schedule:
    6.1. Projected Availability:
    Aligns with GlassFish V2/Sun Java System Application Server 9.1 schedule