Re: [ws-rx] NEW ISSUE: what obligations on RMD for Offered Sequence?

[Daniel Millwood <MILLWOOD@uk.ibm.com>]

Chris,

I agree with this proposal.  Given that the wsrm:Offer is an optimization,
I dont think there should be any expectations from the RMS as to if/how the
RMD will use the offered sequence.

The offered sequence, if accepted, should be treated exactly the same as if
it had been created using a CreateSequence/CreateSequenceResponse flow.
This means it could be terminated at a different time to the sequence on
which it was offered, and another sequence could be created to continue
sending messages.  There would also be no assumptions as to whether the
offered sequence was only used for responses to messages flowed on the
sequence that made the offer.  Any messages destined for the endpoint that
the offered sequence goes to should be able to be sent on the sequence.

I dont think there should be any special ties between the offered sequence
and the sequence that made the offer, once the offered sequence has been
establised.


Thanks,  Dan

WebSphere Platform Development
MP 211
Hursley
Tel. Internal 248617
Tel. External +44 1962 818617
Email. millwood@uk.ibm.com



                                                                           
             Christopher B                                                 
             Ferris                                                        
             <chrisfer@us.ibm.                                          To 
             com>                      ws-rx@lists.oasis-open.org          
                                                                        cc 
             25/08/2005 22:18                                              
                                                                   Subject 
                                       [ws-rx] NEW  ISSUE: what            
                                       obligations on RMD for Offered      
                                       Sequence?                           
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           




Title: What are the obligations on RMD for use (or not) of Offered
Sequence?

Description: When an RMD accepts an offer of a bilateral Sequence, is it
obligated
to use that Sequence for response messages to the endpoint that requested
creation of
the Sequence in which the offer was made?

Justification: The text in section 3.4 makes no mention of the
obligations, if any
that the RMD has in accepting a CreateSequence with an Offer. The text at
480(pdf)
reads:

    /wsrm:CreateSequence/wsrm:Offer
    This element, if present, enables an RM Source to offer a
corresponding Sequence for the reliable
    exchange of messages transmitted from RM Destination to RM Source.

Target: core
Type: design

Proposal: As the wsrm:Offer is intended as an optimization, I believe that
the RMD
should be under no obligation to actually use the offered Sequence.
Similarly, I
believe that it should be made clear in the spec that the RMS MUST NOT
presume that the
offered Sequence will actually be used to ensure that there are no interop
issues that
might arise from one implementation making such an assumption and another
that chooses
not to use the offered Sequence (for what ever reason). I suppose that we
*could*
devise a wsrm:Decline child of wsrm:CreateSequence as a courtesy to the
RMS that made the offer
so that it could reclaim the associated resources rather than having to
wait until the offered
(but unused) Sequence expired. That would make it abundantly clear that
there was
no association. If we pursued the wsrm:Decline, then the text around lines
536-566
will need to be fixed accordingly.

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