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Re: Capabilities in the architecture

From: Francis McCabe <fgm@fla.fujitsu.com>
Date: Fri, 23 Jan 2004 14:41:12 -0800
Message-Id: <3F22BE58-4DF5-11D8-B425-000A95DC494A@fla.fujitsu.com>
Cc: www-ws-arch@w3.org
To: Hugo Haas <hugo@w3.org>

I think that this sounds like a good idea.
It may also tie in quite well with the notion of a service role
Frank

On Jan 23, 2004, at 7:11 AM, Hugo Haas wrote:

> Back in October, I started a discussion about contraints and
> capabilities[1] that never resulted in any text in the document.
>
> I believe that it's important for it to be in the document, as it is
> for example the rationale for solutions like WS-Policy.
>
> Thinking again about my first proposal and the discussion we had on
> the call afterwards, I believe that we can fairly simply address this
> problem, by introducing the concept of "capability" in the service
> oriented model.
>
> Here is my proposal:
>
> ----8<--
> ==========
> Capability
> ==========
>
> - Definition:
>
> A capability is a feature that is declared as supported by an agent.
>
> - Relationships to other concepts:
>
> A capability is
>   a feature
>
> A capability may be referenced in
>   an obligation
>
> A capabilitiy may be described in
>   a service description
>
> - Description:
>
> Web services provide an extensible, decentralized environment.  The
> agents participating into an exchange may therefore implement a wide
> variety of features.
>
> In order for a requester agent and a provider agent to make use of a
> particular feature, they both need to support it.
>
> There may be variation of a particular extension; for example, there
> may be different ways to achieve the reliable delivery of a message.
> The requester and provider entities may therefore need to do some
> negotiation about the features to be used during the exchange by their
> agent. This negotiation may be automatic or manual.
>
> It is therefore necessary for agents to advertize the features they
> support. A supported feature is called a capability. One of the agent
> could request the mandatory use of capability using an obligation.
>
> -->8----
>
> Comments? Frank, you had problems with my first proposal. How does
> this one sound?
>
> Regards,
>
> Hugo
>
>   1. http://www.w3.org/mid/20031016095009.GQ953@w3.org
> -- 
> Hugo Haas - W3C
> mailto:hugo@w3.org - http://www.w3.org/People/Hugo/
Received on Friday, 23 January 2004 17:41:26 GMT

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