First attempt at characterizing policy in the architecture

Hi Frank, Chris, Philippe.

I am sending this to you for a first set of comments before sending it
to www-ws-arch because:
- Frank has a good view of the concepts and relationships in our
  document and has expressed interest in policies.
- Philippe participated actively in the Properties and Features task
  force where they discussed this.
- Chris's name came up when Philippe and I talked with Francisco
  Curbera in Budapest about aligning the abstract models for WSDL 1.2
  and the work on policies.

So, I thought I would take a stab at trying to express policies in
terms of our concepts.

The result is below. It may well be incomplete, which is why I wanted
to get your early feedback before I send to the WSAWG list.

The terminology below is the one from:

  http://dev.w3.org/cvsweb/~checkout~/2002/ws/arch/wsa/wd-wsa-arch-review2.html?rev=1.27&content-type=text/html

------8<----

= Policy =

+ Summary

A policy exposes capabilities and requirements on an agent's behavior
constraining the interactions between agents.

+ Relationship to other elements

policy
  has an
    identifier

policy
  leads to (I am not sure what relationship should go here...)
    contract

policy
  may apply to a(n) (= put constraints on)
    agent | legal entity | message | TBD:Service

policy
  has
    one or more features

+ Description

In a Web service interaction, each requester agent and provider agent
has a set of capabilities and requirements. Those capabilities and
requirements are expressed as features of the architecture.

In order to interact, agents need to find a set of required features
that they all implement.

Policies are sets of features that are used to achieve such a result.

The features expressed in policies can be of different natures. Examples
are:
- Security: expressing requirements for an interaction to be considered
  as secure.
- Trust: expressing requirements for an agent to trust the party 
- Privacy: expressing the intended usage of the data collected as a
  result of an interaction.
- Etc.

[ Note: put links to privacy and security sections above. ]

The examination of the parties' policies results in a contract for the
interaction. Should the processing of the request by the service be
delegated in part or completely, the delegation must respect the terms
of the contracts set with the requester (referring to AR020.5[1]).

+ Open issues

Relationship between description and policy. Is a description derived
from the negotiation of a policy between agents or legal entities?

This is relation to the Properties and Features Task Force task force
work.

------>8----

Note that "good enough to start discussion on www-ws-arch where I will
send my comments" is a fine answer.

Thanks.

Regards,

Hugo

  1. http://www.w3.org/TR/2002/WD-wsa-reqs-20021114#AC020
-- 
Hugo Haas - W3C
mailto:hugo@w3.org - http://www.w3.org/People/Hugo/

Received on Friday, 13 June 2003 07:54:19 UTC