Re: WSDL and pub/sub

Here are some high points from the WS-Discovery spec - I'm speaking on
Web Services Standards (the up-to-the-minute landscape, including
Choreography) at the Washington D.C. XML Users Group this evening, and
had these high points already prepared as part of my presentation:

- WS-Discovery (Web Services Dynamic Discovery) defines a "multicast
discovery protocol" to locate services;

- To find a target service by the type of the target service, a scope in
which the target service resides, or both, a client sends a "probe
message" to a multicast group; target services that match the probe send
a response directly to the client.

- To locate a target service by name, a client sends a resolution
request message to the same multicast group, and again, the target
service that matches sends a response directly to the client;

- To minimize the need for polling, when a target service joins the
network, it sends an announcement message to the same multicast group.
By listening to this multicast group, clients can detect newly-available
target services without repeated probing.

Kind Regards,
Joe Chiusano
Booz | Allen | Hamilton
Strategy and Technology Consultants to the World

Martin Chapman wrote:
> 
> another interesting piece of related work
> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnglobs
> pec/html/ws-discovery.asp
> 
> > -----Original Message-----
> > From: public-ws-chor-request@w3.org
> > [mailto:public-ws-chor-request@w3.org] On Behalf Of Martin Chapman
> > Sent: 17 February 2004 19:20
> > To: david.burdett@commerceone.com; Farrukh.Najmi@Sun.COM
> > Cc: chiusano_joseph@bah.com; UCorda@SeeBeyond.com;
> > Monica.Martin@Sun.COM; andyb@whyanbeel.net;
> > steve@enigmatec.net; public-ws-chor@w3.org
> > Subject: RE: WSDL and pub/sub
> >
> >
> >
> > This discussion is getting off topic for this list!
> >
> > > -----Original Message-----
> > > From: public-ws-chor-request@w3.org
> > > [mailto:public-ws-chor-request@w3.org] On Behalf Of
> > > david.burdett@commerceone.com
> > > Sent: 17 February 2004 17:26
> > > To: Farrukh.Najmi@Sun.COM
> > > Cc: chiusano_joseph@bah.com; UCorda@SeeBeyond.com;
> > > Monica.Martin@Sun.COM; andyb@whyanbeel.net;
> > > steve@enigmatec.net; public-ws-chor@w3.org
> > > Subject: RE: WSDL and pub/sub
> > >
> > >
> > >
> > > Farrukh
> > >
> > > Thanks for the explanation, it makes sense. Here's another
> > > question as I am really trying to get my mind around this ...
> > >
> > > Suppose, that you want to build an auction capability using
> > > the the following services, for example: 1. User Registration
> > > - registers a user 2. Auction Registration - records a
> > > registered user's interest in an auction 3. Bid Placement - a
> > > user that has registered an interest in an auction places a
> > > bid 4. Bid Notification - users that have registered an
> > > interest are notified of successful bids placed 4. Bid Result
> > > - the winner of the auction (if any) and other interested
> > > users are notified of the result of the auction 3. Winning
> > > Bid Payment - the winner of the auction pays, by credit card
> > >
> > > Let's go further and assume that:
> > > 1. There are existing User Registration and Winning Bid
> > > Payment services that the operator of the auction wants to
> > > use 2. Bids are not automatically accepted, for example they
> > > must be higher than any previous bid and perhaps mulitples of
> > > $10, if that what the auction rule says 3. Users must be
> > > registered before they can bid.
> > >
> > > This sounds to me to be more than what the ebXML Resistry was
> > > designed for.
> > >
> > > So some more questions:
> > > 1. Could you sensibly use the pub/sub part of ebXML RR in the
> > > above example. 2. If you can, you still have the problem of
> > > defining how you combine the ebXML RR pub/sub protocol with
> > > other existing protocols to ensure that they occur in the
> > > correct sequence.
> > >
> > > Don't misunderstand me, I do think that ebXML RR has great
> > > value in maintaining information about "static" objects, e.g.
> > > WSDL definitions, schemas, etc, I'm just not sure that it is
> > > the appropriate technology to use for this use case.
> > >
> > > Thoughts
> > >
> > > David
> > >
> > > -----Original Message-----
> > > From: Farrukh Najmi [mailto:Farrukh.Najmi@Sun.COM]
> > > Sent: Tuesday, February 17, 2004 4:39 AM
> > > To: Burdett, David
> > > Cc: chiusano_joseph@bah.com; UCorda@SeeBeyond.com;
> > > Monica.Martin@Sun.COM; andyb@whyanbeel.net;
> > > steve@enigmatec.net; public-ws-chor@w3.org
> > > Subject: Re: WSDL and pub/sub
> > >
> > >
> > > david.burdett@commerceone.com wrote:
> > >
> > > >Monica, Joseph, Ugo et al
> > > >
> > > >A question. Just suppose you wanted to use the ebXML RR spec
> > > with other
> > > >XML documents designed to support the Auction use case I
> > > described earlier, would there be any issues that you can
> > > think of. For example ... would you need to have an ebXML
> > > Registry to store information about Auction objects?
> > > >
> > > >
> > > David,
> > >
> > > Funny you should mention an auction scenario and ebXML
> > > Registry. See a
> > > recent exchange below where I used the same scenario in the
> > > context of
> > > ebXML Registry event notification.
> > >
> > > I feel that ebXML Registry event notification could be used
> > > to support
> > > multi-party collaboration scenarios as the next logical step
> > > from binary
> > > collaborations exemplified by ebXML Messaging and SOAP.
> > >
> > > As it currently stands, registry events are only triggered when a
> > > CREATE/UPADTE/DELETE operation occurs
> > > in the registry. For example a BiddableObject must be written to
> > > registry to represent that something is open for bids.
> > > Bidders would be
> > > subscribed to BiddableObjects and will be notified. They can
> > > then write
> > > Bid objects to the registry. The auctioneer would be
> > > subscribed to Bids
> > > for "their" BiddableObjects and will be notified when a Bid
> > > is placed.
> > > They would have to write a BidResult object to registry
> > when bidding
> > > closes and all Bidders would be notified of the BidResult.
> > >
> > > So yes several objects would have to be written to the
> > > registry in order
> > > to support this scenario.
> > >
> > > --
> > > Regards,
> > > Farrukh
> > >
> > >
> > >
> > > -------- Original Message from Farrukh on regrep in reply to
> > > Joe  --------
> > > Subject:    Re: [regrep] Direct Data Exchange vs. SOA
> > > Date:       Wed, 11 Feb 2004 10:50:12 -0500
> > > From:       Farrukh Najmi <Farrukh.Najmi@Sun.COM>
> > > To:         Chiusano Joseph <chiusano_joseph@bah.com>
> > > CC:         regrep@lists.oasis-open.org
> > <regrep@lists.oasis-open.org>
> > > References:         <402A4C2C.C65CF5F1@bah.com>
> > >
> > >
> > >
> > > Chiusano Joseph wrote:
> > >
> > > >I have an inquiry that is not directly related to our
> > > mission here, but
> > > >I hope to get some good insight in response please:
> > > >
> > > >Let's say we have a purchase order process between trading
> > > partners (PO
> > > >sent, Invoice received). There are (for the purposes of this
> > > inquiry) 2
> > > >possible ways to handle this process:
> > > >
> > > >(1) Direct Data Exchange (create XML documents based on a common
> > > >schema, and exchange them between trading partners)
> > > >
> > > >(2) SOA (have a purchase order/invoice shared service that is
> > > >discovered in a registry, etc.)
> > > >
> > > >My inquiry is: What would drive an organization to use one
> > > approach or
> > > >the other, from both a business and technical standpoint?
> > > For instance,
> > > >would "critical mass of services and/or trading partners" be
> > > a driver
> > > >for SOA vs. direct data exchange?
> > > >
> > > >
> > > >
> > > The second approach allows for multi-party colaboration instead of
> > > binary collaboration.
> > > It would rely on Registry Event notification. An example would be a
> > > bidding or auction scenario.
> > >
> > >
> > >
> > >
> > >
> > >
> >
> >

Received on Wednesday, 18 February 2004 17:15:54 UTC