i009 use cases

[Christopher B Ferris <chrisfer@us.ibm.com>]

I have the AI [1] to capture the use cases for issue i009 [2]

Allow me to kick off the discussion on the list with the following use 
case:

UC1 Application Source (AS) requires that all messages be processed by the 
Application Destination (AD)

The RM protocol is an AtLeastOnce protocol as perceived between the RMS 
and RMD. However, the
RMD is free to implement whatever level of QoS with respect to the AD that 
the AD deems appropriate.
For instance, the RMD might be resource constrained, and offer the AD an 
AtMostOnce DA using a
FIFO algorithm to discard unprocessed messages it has received once some 
threshold of constrained
resource (such as message store) has been exceeded.

Thus, the source should be able to discern the DA QoS in effect at the 
destination endpoint so that it can
choose whether the DA QoS is adequate to its requirements and opt to 
either use the service, or not.

An AS that required ExactlyOnce DA QoS could, via some unspecified means, 
instruct the RMS only to 
use a service whose RMD implemented ExactlyOnce DA. The RMS would then 
inspect the prospective
endpoint's DA as advertised in policy for a match on the wsrm:ExactlyOnce 
delivery assurance.

Thoughts?

[1] 
http://www.oasis-open.org/apps/org/workgroup/ws-rx/members/action_item.php?action_item_id=979
[2] 
http://www.oasis-open.org/apps/org/workgroup/ws-rx/download.php/13809/ReliableMessagingIssues.xml#i009

Cheers,

Christopher Ferris
STSM, Emerging e-business Industry Architecture
email: chrisfer@us.ibm.com
blog: http://webpages.charter.net/chrisfer/blog.html
phone: +1 508 377 9295