discussion of issue i009

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

All,

This email is intended to start a discussion on issue i009 [1].

The issue has to do with providing the RMD with the capacity to advertise 
its DA QoS. It is somewhat related to 
issue i024, raised by Ashok. However, I don't believe that the resolutions 
need to be tied to one another.

Basically, there is currently no specified means of declaring the DA 
applied at a given RMD endpoint. It has been
suggested that the RMS (or AS) might have a vested interest in knowing, a 
priori to establishing a Sequence with
an RMD what DA would be applied. For instance, it may require that the 
messages be processed InOrder. If the
RMD were not enforcing InOrder DA at the RMD, then the source endpoint 
might choose not to engage with that
endpoint.

I would propose that one way to resolve this would be to define RM policy 
assertions that specify the DA.
e.g. a psuedo-schema for this would be as follows:

<wsrm:RMAssertion>
  <wsrm:DeliveryAssertion mode="[AtLeastOnce|AtMostOnce|ExactlyOnce]" 
ordered="[xs:boolean]"? ... >
    ...
  </wsrm:DeliveryAssertion>?
  ...
</wsrm:RMAssertion>

Thus, an endpoint could declare its DA QoS in the policy statement 
associated with the endpoint.

Thoughts?

[1] 
http://www.oasis-open.org/apps/org/workgroup/ws-rx/download.php/14329/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