Re: message exchange patterns and # of parties


I think Sanjiva was counting both the client and the service when he said 
"two parties".

At 01:08 PM 9/10/2003 -0400, Amelia A. Lewis wrote:

>On Wed, 10 Sep 2003 22:55:36 +0600
>Sanjiva Weerawarana <> wrote:
> > I remember some discussion during the last F2F about the number
> > of parties that may be involved with a single message exchange
> > pattern. I think I was arguing against having more than two
> > parties as that's getting more into choreography space.
>Err, umm.  No, in my opinion, any more than a description of more than
>one party's participation is choreography.
> > What did we decide? Are patterns allowed to have more than 2
> > parties participating in a single pattern?
>So far as I can recall, this was not one of the things ruled out.  Each
>pattern description must now contain identifications of participating
>nodes, but there is no ruling out of something such as the "third-party
>request/response" (A -> Service -> C).
>Multicast is apparently now to be handled by ignoring it, on the basis
>that the fact of multicast is not important to *both* parties.  So an
>output-only MEP may actually be delivered to multiple recipients; the
>MEP is in this case construed to model the interaction between the
>service and *each* receiving node (the service may send a single
>message, and multiple recipients may receive it, but this information is
>considered to be not visible in the description of the exchange
>Amelia A. Lewis
>Architect, TIBCO/Extensibility, Inc.

David Booth
W3C Fellow / Hewlett-Packard
Telephone: +1.617.253.1273

Received on Thursday, 11 September 2003 11:17:33 UTC