Re: [sca-assembly] Fwd: Conversational services

[Simon Nash <oasis@cjnash.com>]

Just one comment on this long and very interesting thread
(other text removed for readability).

   Simon

David Booz wrote:
> Thanks for the reply.
> 
> See inline *<dab> </dab>*
> 
> Dave Booz
> STSM, BPM and SCA Architecture
> Co-Chair OASIS SCA-Policy TC and SCA-J TC
> "Distributed objects first, then world hunger"
> Poughkeepsie, NY (845)-435-6093 or 8-295-6093
> e-mail:booz@us.ibm.com
> 
> Inactive hide details for Jim Marino ---12/23/2008 01:24:11 PM---Thanks 
> Dave. I'll try to comment inline inline.Jim Marino ---12/23/2008 
> 01:24:11 PM---Thanks Dave. I'll try to comment inline inline.
> 
> 
> From:	
> Jim Marino <jim.marino@gmail.com>
> 
> To:	
> OASIS Assembly <sca-assembly@lists.oasis-open.org>
> 
> Date:	
> 12/23/2008 01:24 PM
> 
> Subject:	
> Re: [sca-assembly] Fwd: Conversational services
> 
(cut)
> 
>              >> Another way I have seen conversations propagated is how
>             Microsoft Durable Services work using service-provider
>             tokens. In this model, they have decoupled the
>             conversational model from how correlation is transmitted (in
>             SOAP headers via WsHttpContextBinding, or using cookies via
>             BasicContextBinding). With this approach, one issue is that
>             the SCA infrastructure will have to wait for a back channel
>             message containing the token before a second invocation is
>             delivered.
>             Two problems here. 1) This is a new protocol, that is not
>             standardized, and 2) you will have to define how this works
>             for each binding spec.
> 
> Aren't we already doing this for callbacks?
> *<dab> We don't do protocols in SCA. We aren't standardizing the 
> callback over WS semantic.We have an example of one way that a stateless 
> callback could be done over WS. There is no requirement that any vendors 
> do it this way. </dab>*
> *<dab> If you're suggesting that conversations as we have them today 
> could be an optional compliance point then I would probably agree to 
> that.... </dab>*
 >
If you mean "as we have them today in all the SCA specs", I would
be very concerned about this because of the complexity it would add
(e.g., in the SCA Java spec).  If you mean "as we have them today
in the assembly spec", the complexity isssue is less significant,
but what would the compliance point be?  The assembly spec defines
some syntax for indicating that services are conversational, but it
doesn't define any testable semantics for conversational services.

   Simon