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RE: Some proposed definitions of "web service" based on the call toda y

From: Anne Thomas Manes <anne@manes.net>
Date: Sun, 20 Apr 2003 08:28:44 -0400
To: "Newcomer, Eric" <Eric.Newcomer@iona.com>, "Christopher B Ferris" <chrisfer@us.ibm.com>, <www-ws-arch@w3.org>
Message-ID: <ECEDLFLFGIEENIPIEJJPAEKPEAAA.anne@manes.net>
So Eric -- What is a CORBA service? Is it the API, or the agent that
implements the service? Or is it both?
  -----Original Message-----
  From: www-ws-arch-request@w3.org [mailto:www-ws-arch-request@w3.org]On
Behalf Of Newcomer, Eric
  Sent: Saturday, April 19, 2003 3:13 PM
  To: Christopher B Ferris; www-ws-arch@w3.org
  Subject: RE: Some proposed definitions of "web service" based on the call
toda y


  I still have the problem with defining the agent as the service.  The
service is mapped or transformed onto the agent.  Saying that a Web service
is an interface to an agent, a representation of an agent, or a description
of an agent are all ok with me, but I can't (for example) see anything in
SOAP, WSDL, etc. that defines what the agent is or has to be.
    -----Original Message-----
    From: Christopher B Ferris [mailto:chrisfer@us.ibm.com]
    Sent: Friday, April 18, 2003 8:00 AM
    To: www-ws-arch@w3.org
    Subject: Re: Some proposed definitions of "web service" based on the
call toda y



    I would prefer that we not include references to version numbers in the
definition, as these will
    change over time. I think that the acronyms should suffice. Secondly, I
thinn that qualifying SOAP by
    calling out the XML Infoset and processing model suggests that other
aspects of SOAP are either
    not used, or not allowed, or who knows what. I think that it is
sufficient to say just SOAP. Finally, since
    we have spent some time discussing the various types of ways in which
people have been using the term,
    I felt that it is probably worthwhile that we share some of these
alternate uses with the readers of the
    WSA and give them a little more background.

    How 'bout this:
    ------------------------------------------------------------------------
-
    The term "Web service" has been used to refer to a wide variety of
things,
    and it is clear that not all people share the same understanding and
definition.
    For some, it has meant simply the exchange of XML over the Web,
typically using HTTP.
    For others, it has meant simply the exchange of SOAP messages, typically
using HTTP,
    or some software component that has been described using WSDL. In a
sense, all of these
    things might be considered to be "Web services", and the Working Group
does not
    preclude the use of the term to describe these sorts of things.
Nevertheless, for
    the purposes of this document, we will define the term Web services as
follows:

    [Definition: Web service - an executable software agent that is
identified by
    a URI and whose interface and binding(s) are described using WSDL. Other
software agents
    interact with a Web service in a manner prescribed by its WSDL
description, using SOAP.]

    ------------------------------------------------------------------------
---------------------------------------------------------------------------

    Now, this definition probably deserves some further explanation in order
to say things like  "there's nothing
    to preclude the use of other protocols (than SOAP) to interact with a
Web service... for the purposes of this document, we simply
    aren't going to go there" and "while the definition requires the use of
WSDL, it does not preclude the use of
    other technologies or XML vocabularies for its description. however, for
the purposes of this document, we
    aren't going to go there..."

    Again, it might be nice to solve the equation for all possible solutions
to WS = U + Xd + Xm (a web service is identified
    by a URI and described using XML and interacted with using XML messages)
IMO this represents a daunting
    task. We should be focused on defining an architecture that leverages
the technologies being developed
    in our sibling WGs in the Web Services Activity in its realization.

    Cheers,

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

    www-ws-arch-request@w3.org wrote on 04/17/2003 05:36:27 PM:

    >
    > Whew, that was fun :-(  Although it got better when we stumbled on the
    > "instant straw poll in IRC" idea; we should do that more often.  I'd
say
    > that in general, anyone who has the "floor" in the speaker queue may
propose
    > one of those by typing the question into IRC; those not on IRC can ask
to
    > have their vote recorded by someone who is.
    >
    > Let me throw out some proposals that reflect the various opinions I
heard
    > today; without my co-chair hat on, I could live with either of them:
    >
    >
===========================================================================
    > The term "web service" is used in a wide variety of ways by different
    > people, and we will not presume that the definition used here is
consistent
    > with all of them.  Nevertheless, for the purposes of this document, we
will
    > use the term to mean the following: A Web service is [an interface to
?] an
    > executable software agent that is designed to be used by another
software
    > agent.  A Web service is
    > identified by a URI, and MUST be [capable of being ?] formally defined
in
    > WSDL 1.2.  A software agent interacts with an  Web service in the
manner
    > prescribed by the formal definition, using the XML Infoset and
processing
    > model defined by SOAP 1.2.
    >
    > [Chris said some things about SOAP being general enough to describe
any
    > reasonable "web service" interaction that I didn't capture very well
...
    > maybe he can refresh my memory.]
    >
    >
==========================================================================
    >
    > The term "web service" is used in a wide variety of ways by different
    > people, but there is a rough consensus along the following lines: A
Web
    > service is an interface to an executable software agent that is
designed to
    > be used by another software agent.  A Web service is identified by a
URI,
    > and has a definition in a language sufficient to describe the
interface to
    > developers of client agents. A software agent interacts with a Web
service
    > in the manner that is consistent with the description, using standard
    > protocols.
    >
    > That definition of "web service" is not sufficiently precise or
rigorous for
    > architectural purposes, however.  We will use a more restrictive term
to
    > describe the scope of the architecture described here: "Extensible XML
Web
    > Services", abbreviated XWS.   the purposes of this document, we will
use the
    > term to mean the following: An XWS is an interface to an executable
software
    > agent that is designed to be used by another software agent.  An XWS
is
    > identified by a URI, and MUST be capable of being formally defined in
WSDL
    > 1.2.  A software agent interacts with an  Web service in the manner
    > prescribed by the formal definition, using the XML Infoset and
processing
    > model defined by SOAP 1.2."
    >
    > ["XWS" is essentially a placeholder for some term ... I don't care
what it
    > is, but it must specifically describe the "MUST" constraints specified
by
    > the WSA.]
    >
    >
==========================================================================
    > Of course, improved definitions are solicited.
    >
Received on Sunday, 20 April 2003 08:27:25 GMT

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