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RE: Counting noses on "is SOAP and/or WSDL intrinsic to the de finition of Web service"

From: Christopher B Ferris <chrisfer@us.ibm.com>
Date: Thu, 5 Jun 2003 07:23:04 -0400
To: www-ws-arch@w3.org
Message-ID: <OF945B341F.9B5E3AF3-ON85256D3C.003C1E2E-85256D3C.003E8A3E@us.ibm.com>

Hao,

Plain XML does not have a process model as does SOAP (or, you could say it 
has
many). If there are intermediaries, how are they constrained? Is there an 
order
to processing aspects of the content? If I want to digitally sign the 
message, where
does that go? What if I want to target certain aspects of the message at 
particular
nodes acting in particular roles? How many gazillion ways do you think 
that could
be expressed in plain ole XML?

Sure, I suppose you could say "use HTTP and have the entity body of the 
messages
be the same as the SOAP:Body content, just plain ole XML", but then the 
issue of extensible 
HTTP header fields rears its ugly head. There's no way to tell your 
extension header 
called 'foo' from mine with the same name and they could have wildly 
different semantics. 
Sure, we could spend a whole lot of time and energy re-inventing HTTP to 
accomodate the 
types of things that SOAP has been designed to do, but that was largely 
why SOAP was 
created in the first place!

With plain ole XML, what we have is total anarchy. I can tell you that 
nearly every vocabulary
has the rough equivalent of a body and headers, each with its own process 
model and each 
with its own structure. Take a look at early RosettaNet, OTA, SIF, HL7, 
and OAG work among
others. You will note a pattern, but you will also note that each had its 
own thing going on. How 
does one write software for this wide range of possible formats unless it 
is specific to a given
format?

It simply doesn't scale, and it is simply non-interoperable on a broad 
scale. Certainly,
you would not want to have to imlement an infinite number of possible 
reliable messaging
engines, one for each vocabulary that someone decided to concoct? Same for 
security,
for business process choreography, etc. That's what middleware is for, to 
do the heavy
lifting for common tasks, removing the need for the application programmer 
to deal with
such things (which are often way above their capacity to handle correctly 
and efficiently
anyway).

So, in short, plain ole XML as payload is not interoperable other than the 
fact that 
XML itself, and XML parsers are (mostly).

Cheers,

Christopher Ferris
STSM, Emerging e-business Industry Architecture
email: chrisfer@us.ibm.com
phone: +1 508 234 3624

www-ws-arch-request@w3.org wrote on 06/05/2003 01:06:03 AM:

> ok, a really dumb question: why would SOAP binding be more interoperabe 
than
> plain XML binding? 
> 
> Hao
> 
> -----Original Message-----
> From: Ugo Corda [mailto:UCorda@SeeBeyond.com]
> Sent: Thursday, June 05, 2003 2:32 PM
> To: Jeff Mischkinsky; David Orchard; www-ws-arch@w3.org
> Subject: RE: Counting noses on "is SOAP and/or WSDL intrinsic to the
> definitio n of Web service"
> 
> 
> 
> Yes, that's my point too.
> 
> Ugo
> 
> > -----Original Message-----
> > From: Jeff Mischkinsky [mailto:jeff.mischkinsky@oracle.com]
> > Sent: Wednesday, June 04, 2003 8:34 PM
> > To: Ugo Corda; David Orchard; www-ws-arch@w3.org
> > Subject: RE: Counting noses on "is SOAP and/or WSDL intrinsic to the
> > definitio n of Web service"
> > 
> > 
> > I think the point here is that for interoperability reasons 
> > we need to 
> > require at least a SOAP binding. Other bindings are possible 
> > and useful in 
> > addition.
> >    jeff
> > 
> > At 03:08 PM 6/4/2003, Ugo Corda wrote:
> > 
> > >By the same logic, would a WSDL binding to plain Java calls 
> > (sender and 
> > >receiver within the same Java process) correspond to a Web 
> > service? Or a 
> > >WSDL binding to RMI, or to DCOM, or to IIOP? Certainly possible WSDL 
> > >bindings cover a lot of territory ...
> > >
> > >Ugo
> > >
> > > > -----Original Message-----
> > > > From: David Orchard [mailto:dorchard@bea.com]
> > > > Sent: Wednesday, June 04, 2003 2:47 PM
> > > > To: 'Jeff Mischkinsky'; 'Christopher B Ferris'; www-ws-arch@w3.org
> > > > Subject: RE: Counting noses on "is SOAP and/or WSDL 
> > intrinsic to the
> > > > definitio n of Web service"
> > > >
> > > >
> > > >
> > > > Another question to the +10ers.  If a WSDL file can describe
> > > > a service that
> > > > uses HTTP GET and POST and not SOAP, as in
> > > > http://www.w3.org/TR/wsdl#_http,
> > > > is that service a web service?  Under the +10 definition, it
> > > > isn't.  So the
> > > > "Web service" description language describes Web service +
> > > > something else.
> > > > What do you call that something else that WSD can describe
> > > > but isn't a Web
> > > > service?  Which also means that we actually have a Web
> > > > Service + some other
> > > > thing Description Language.
> > > >
> > > > Dave
> > > >
> > >
> > 
> > 
> [attachment "InterScan_Disclaimer.txt" deleted by Christopher B 
Ferris/Waltham/IBM] 
Received on Thursday, 5 June 2003 07:23:15 GMT

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