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RE: Label for Top Node of "triangle diagram"

From: Heather Kreger <kreger@us.ibm.com>
Date: Fri, 27 Sep 2002 15:46:56 -0400
To: "Cutler, Roger (RogerCutler)" <RogerCutler@ChevronTexaco.com>
Cc: www-ws-arch@w3.org
Message-ID: <OFD8590BE5.06698FEE-ON87256C41.006C1CF8@us.ibm.com>





The triangle is a logical look at some roles:
requester/provider/registry-cloud-thing, some communications: publish,
find, interact, and some artifacts: service, service description.

The fact that you can implement any of these as a web service itself is
orthogonal.

Other things we seem to be introducting, like intermediaries, can also be
realized as web services. In fact, an intermediary might function both as
an intermediary and a useful service in his own right accessed directly by
other web service requesters.

And yes, I can seem many useful ways to realize some of our other roles as
web services (security manager? etc.)

This does not break my head. This just means that the fundamental
characteristics we define for web services can be shared by other roles as
well. Its a feature, not a bug. :-)

Heather Kreger
Web Services Lead Architect
STSM, SWG Emerging Technology
kreger@us.ibm.com
919-543-3211 (t/l 441)  cell:919-496-9572


"Cutler, Roger (RogerCutler)" <RogerCutler@ChevronTexaco.com>@w3.org on
09/27/2002 02:50:02 PM

Sent by:    www-ws-arch-request@w3.org


To:    "'Dave Hollander'" <dmh@contivo.com>, www-ws-arch@w3.org
cc:
Subject:    RE: Label for Top Node of "triangle diagram"




You guys are making my head hurt.  It just became clear to me that the
"cloud" is, itself, a web service.  So somehow we are defining web services
in some kind of recursive way?

Ouch!

I'm liking the triangle less an less by the minute.  Sorry -- maybe I'm
just
misunderstanding here, but ...

If the cloud is, in fact, a web service -- then it seems to me that there
are two and only two reasonable diagrams for a web service, the cloud
simply
being a replication of one of these fundamental components used for the
special purpose of discovering and describing the availability of web
services:

1)Requestor/Receiver <-> Responder

2)Requestor -> Responder -> Receiver

-----Original Message-----
From: Dave Hollander [mailto:dmh@contivo.com]
Sent: Friday, September 27, 2002 1:05 PM
To: www-ws-arch@w3.org
Subject: RE: Label for Top Node of "triangle diagram"



I agree that registries are not the only way to implement discovery! That
is
why i quoted "place", but apparently I was not clear. I think we
intuitively
knew this when we agreed that a --cloud-- was the best graphical icon for
this node.

Advertising - web pages advertise by being part of a hypertext network. If
I
want a search engine to find my page, I have to
make sure it is either in its explicit listing of pages (registry) or
linked
to from a page that is.

Web services are not hypertext--there is no way to start at a
node and explore links described at that node. Hence they need to advertise
in some form...either by phone, email to other service developers or
describe themselves to a well known mechanism (typically a registry).


Description - I am very interested in where and how people
believe description happens. Is it an atomic transaction-- fully described
in one interchange--or composite? Who is
responsible for what roles? How can you use a --cloud-- to
find a service if the --cloud-- does not provide some description? Will we
have to inquire directly to each service to select between them?  Is
description narrowly defined as the data in WSDL or does it include UDDI
concepts and others? I prefer the broader sense.


"Advertising and Discovery Mechanisms" - I could live with this but am not
afraid to use "services" either. I think we should describe them as
services, and as we add security, management, QOS etc we will end up
describing services. But that is a debate for a later day.


DaveH

-----Original Message-----
From: Ricky Ho [mailto:riho@cisco.com]
Sent: Friday, September 27, 2002 11:03 AM
To: Dave Hollander; www-ws-arch@w3.org
Subject: RE: Label for Top Node of "triangle diagram"


I think "registry" (in the way you describe it) is one way to implement a
"discovery" mechanism.  The "roles" that you describe about a "registry"
implies a centralized place where information is kept.  But "registry"
shouldn't be the ONLY way to implement discovery.  For example, a
peer-to-peer approach can be used to implement the discovery mechanism
...  My response inline ...

>The roles, as I understand them, are:
>1) a "place" to advertise a service's availability

[Ricky]
Do we really require the service to explicitly "ADVERTISE" its availability
in a particular "PLACE" ?  Think about a web page, you don't need to
advertise it and still able to be found in search engine.  What can't the
service provider be using similar mechanism ?

>2) an agency that brokers services' descriptions

[Ricky]
Like WSIL, we can discover the service's description at the endpoint.  It
doesn't have to be in a separate agency.

>3) a "place" to discover what services are availabile

[Ricky]
Again, it doesn't has to be "a place"


>Are these right?
>
>If so, my preferences:
>
>1) Advertising and Discovery Services

[Ricky]
By the term "service", are you implying it has a WSDL description, and a
particular endpoint address where the service is provided ?
Or are we actually talking about an "Advertising and Discovery Mechanism" ?

>2) Services Description and Discovery

[Ricky]
They sounds to be different animals.

>3) Services Registries

[Ricky]
This sounds to me strongly implying a "separate place" which I don't think
is a necessary distinction.

Rgds, Ricky
Received on Friday, 27 September 2002 15:47:34 GMT

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