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RE: Label for Top Node of "triangle diagram"

From: Dave Hollander <dmh@contivo.com>
Date: Fri, 27 Sep 2002 11:04:34 -0700
Message-ID: <BD52C6379806D51188DD00508BEEC96C012A0924@mail.contivo.com>
To: www-ws-arch@w3.org

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 14:09:20 GMT

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