RE: potential users of web services

I largely agree with Anne's definition of Web service.  Here is some
further definition:

The term Web service was created to contrast with two earlier
technologies.  On the one hand, it identifies a distinction from "Web
site" in that a Web site serves pages, typically in HTML, for display in
a browser to a human, while a "Web service" offers a computation
directly to anther computer, with no special expectation that the
computation will be used in a browser or for display to a human. Web
services are not computer-to-human but computer-to-computer.  There is
general consensus that Web services use SOAP and XML, or at least
similar computer-to-computer notations, not HTML or other
computer-to-human notations. On the other hand, "Web service" identifies
a distinction from earlier forms on computer-to-computer interaction
that were bound to particular platforms or programming languages. Web
services are services offered computer-to-computer in a
platform-independent and language neutral manner, via the sending of
messages of definite format, meaning that a new set of protocols need to
be invented, protocols differing from language-and-platform-associated
protocols such as DCOM or Java RMI.

-----Original Message-----
From: Allan Doyle [mailto:adoyle@intl-interfaces.com] 
Sent: Friday, April 05, 2002 6:18 AM
To: www-ws@w3.org
Subject: RE: potential users of web services

I've been following this thread with interest. I was doing a
presentation on Web Services for some people I work for and one of the
things I had to do was define what a Web Service is. I took the easy
way out and said that some people think it has to be fully buzzword
compliant and others think that any machine-to-machine interaction
over the internet is a Web Service. It's clearly a term that has
fallen into the hands and imaginations of the marketing departments.

On Friday 2002-04-05 at 15:33:24(+1000) Hao He wrote:
 >  
 > >"Web Services, the session told us, are not necessarily in XML and
do not
 > have to use SOAP, they just >describe opening up your internal
processes."
 >  
 > I would agree with this statement in principal but not in practise.
As you
 > pointed out, it is essentially important for web services to be
loosely
 > coupled.  For that reason, it is really difficult not to use XML for
 > messaging if soneone does not want to reinvent the wheel.

Within the OGC, we developed a service known as "WMS" (Web Map
Service [1][2]). It fully specs out the format of an HTTP GET request
and you
get back a rendered map as a JPEG, PNG, etc. XML is used so the client
can ask the server what kinds of maps it can produce. But the requests
are done with GET. (HTTP POST of XML encodings of the request have
been proposed). The interface follows REST [3] principles (although we
did
not know that at the time).

I would say that a service followig REST principles even if it does
not use XML in the request or the response still counts as a web
service.

	Allan

[1] http://www.opengis.org/techno/specs/01-068r3.pdf
[2] http://www.intl-interfaces.net/cookbook/WMS/
[3] http://internet.conveyor.com/RESTwiki/moin.cgi


 > 
 > As to SOAP, it has a strong "RPC" style although the later version is
moving
 > away from it, which is a good thing.  So SOAP is not really required.
BTW, I
 > just received Anne's email and I agree with her again!
 > 
 > Hao
 > 
 > 
 > -------------------------------------------------
 > 
 > 
 > Seems to me that SOAP and XML are pretty required to be called a Web
 > service. Otherwise, it's a distributed app, but not the new loosly
coupled
 > thing we are all working on.
 >  
 > Thanks,
 > Keith
 >  
 > [1]
http://www.webservicesarchitect.com/content/articles/wiggers03.asp 
 > 
 > 	-----Original Message----- 
 > 	From: Anne Thomas Manes [mailto:anne@manes.net] 
 > 	Sent: Thursday, April 04, 2002 5:48 PM 
 > 	To: Hao He; thomi@di.uoa.gr; www-ws@w3.org 
 > 	Subject: RE: potential users of web services 
 > 
 > 	+1 
 > 
 > 	I was struggling with that word. I was originally going to call
it
 > simply 
 > 	software -- trying not to  imply any level of granularity, but
then
 > I 
 > 	thought -- well, it might actually be implemented using firmware
or 
 > 	hardware. So I went with the word component. Perhaps it might be
 > best to 
 > 	call it a unit of work (although I don't want to imply that it
 > supports 
 > 	transaction semantics). 
 > 
 > 	Anne 
 > 
 > 	> -----Original Message----- 
 > 	> From: www-ws-request@w3.org [mailto:www-ws-request@w3.org]On
 > Behalf Of 
 > 	> Hao He 
 > 	> Sent: Thursday, April 04, 2002 7:35 PM 
 > 	> To: 'Anne Thomas Manes'; thomi@di.uoa.gr; www-ws@w3.org 
 > 	> Subject: RE: potential users of web services 
 > 	> 
 > 	> 
 > 	> I agree most with Anne except one tiny bit: 
 > 	> 
 > 	> I would say that a web service is a service provided by one or
 > more 
 > 	> components that exposes 
 > 	> a programmatic interface.  A compoent itself is not the
service. 
 > 	> Service is 
 > 	> the functionality that defined in the interface. 
 > 	> 
 > 	> 
 > 	> Hao 
 > 	> 
 > 	> -----Original Message----- 
 > 	> From: Anne Thomas Manes [mailto:anne@manes.net] 
 > 	> Sent: Friday, April 05, 2002 5:05 AM 
 > 	> To: thomi@di.uoa.gr; www-ws@w3.org 
 > 	> Subject: RE: potential users of web services 
 > 	> 
 > 	> 
 > 	> Thomi, 
 > 	> 
 > 	> Ask five people the definition of "web service" and you'll get

 > 	> six answers. 
 > 	> 
 > 	> I generally describe a web service as a service that
communicates
 > over the 
 > 	> web. A service is a component that exposes a programmatic
 > interface. The 
 > 	> service interface must be described; and the service 
 > 	> implementation must be 
 > 	> discoverable. 
 > 	> 
 > 	> When you relate this abstract definition to current
technologies,
 > you can 
 > 	> implement a web service by creating a service that exposes a
SOAP 
 > 	> interface, 
 > 	> which is described by WSDL, and which is registered in UDDI.
But 
 > 	> I wouldn't 
 > 	> want to use current technologies to *define* the basic
concept. I 
 > 	> also don't 
 > 	> think that it's essential to use any of these technologies to
 > create a web 
 > 	> service. I can certainly create a web service using XML-RPC or

 > 	> RosettaNet or 
 > 	> a host of other technologies. 
 > 	> 
 > 	> That said, I would concur that web services are intended to be
 > consumed by 
 > 	> applications rather than humans. But keep in mind that a user
 > interface is 
 > 	> an application. If I wanted to arrange food for 500 people for

 > 	> two weeks in 
 > 	> Dubai, I would use a catering application, which in turn uses
web
 > services 
 > 	> to find caterers that can provide services in Dubai. The UI
isn't
 > the web 
 > 	> service. The UI uses web services to accomplish its work.
Hence 
 > 	> an ASP page 
 > 	> or HTML form aren't web services, they are an interface to web
 > services. 
 > 	> 
 > 	> Best regards, 
 > 	> 
 > 	> Anne Thomas Manes 
 > 	> CTO, Systinet 
 > 	> 
 > 	> > -----Original Message----- 
 > 	> > From: www-ws-request@w3.org [mailto:www-ws-request@w3.org]On

 > 	> > Behalf Of Thomi Pilioura 
 > 	> > Sent: Thursday, April 04, 2002 9:09 AM 
 > 	> > To: www-ws@w3.org 
 > 	> > Subject: potential users of web services 
 > 	> > 
 > 	> > 
 > 	> > Hi all, 
 > 	> > 
 > 	> > I'm little confused about the notion of the term "web
services".
 > 
 > 	> > When I'm reading papers related to UDDI,WSDL,SOAP they
present 
 > 	> > web services 
 > 	> > as a new age of distributed computing and as such they are
only 
 > 	> useful to 
 > 	> > developers (who are trying to build web applicattions) and
not
 > to the 
 > 	> > end-users. But when I'm reading papers related to DAML-S the
 > idea I'm 
 > 	> > getting for web services is different. They are also useful
to 
 > 	> > end users as 
 > 	> > it shown by DAML-S motivating scenarios: 
 > 	> > 
 > 	> > Web service discovery 
 > 	> > Find me a shipping service that transports goods to Dubai. 
 > 	> > 
 > 	> > Web service invocation 
 > 	> > Buy me 500 lbs. powdered milk from www.acmemoo.com 
 > 	> > 
 > 	> > Web service selection, composition and interoperation 
 > 	> > Arrange food for 500 people for 2 weeks in Dubai. 
 > 	> > 
 > 	> > Web service execution monitoring 
 > 	> > Has the powdered milk been ordered and paid for yet? 
 > 	> > 
 > 	> > There are also numerous papers that use the term service
(and
 > not "web 
 > 	> > service") and are talking about UDDI, WSDL and DAML-S.
What's
 > the 
 > 	> > difference 
 > 	> > between "web service" and "service" if both of them work
over 
 > 	> > Internet? For 
 > 	> > example, a search engine (such as google) is a service, but
when
 > it is 
 > 	> > described in WSDL, published in UDDI and can be invoked
using 
 > 	> > SOAP becomes a 
 > 	> > web service? Ia a asp or an HTML form a service or a web
 > service? 
 > 	> > 
 > 	> > In summary which are the potential users of web services
(web
 > service 
 > 	> > providers, developers, end-users)? 
 > 	> > 
 > 	> > could you please shed some light on this? 
 > 	> > regards 
 > 	> > Thomi Pilioura 
 > 	> > 
 > 	> > 
 > 	> > 
 > 	> > 
 > 	> 
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-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Allan Doyle                         http://www.intl-interfaces.com
adoyle@intl-interfaces.com

                                                   

Received on Friday, 5 April 2002 12:10:49 UTC