Summary: Web Services Constraints and Capabilities Workshop

On October 12th and 13th, the W3C held a Workshop on Constraints and 
Capabilities for Web Services[1]. Over 50 participants discussed the 
had a wide-ranging discussion, but generally agreed upon addressing a 
restricted set of today's issues in Web services (e.g., security, 
management, internationalisation) while allowing extensibility for the 
future. Of particular interest was the exact level of functionality -- 
from conjunction and disjunction, negation, through to arithmetic and 
relational operators -- provided by such a framework. Many existing 
solutions, such as WS-Policy, address conjunction and disjunction, 
leaving more advanced functionality to future extensions. Others, such 
as Rei, address more. Participants agreed that an immediate solution is 
preferable, but were more diverse in their opinions regarding the 
functionality needed in such a first cut. However, there was general 
agreement that basing work on an existing solution, rather than 
starting fresh, is more likely to produce successful results.

Most participants agreed with the following recommendations:
  - a Working Group should start sooner rather than later
  - More than one Working Group may be needed to satisfy the diverse 
requirements in this area
  - the Working Group should focus on develop a framework for the 
constraints and capabilities.
  - Such a Working Group should focus on a framework for constraints and 
capabilities; specific vocabularies should be left to other 
specifications' developers. For example, internationalisation 
assertions should be left to an i18n WG.
  - Such a Working Group should, however, provide guidelines for the 
benefit of assertion authors.
  - The expression of constraints and capabilities shouldn't be 
restricted to any particular mechanism; e.g., SOAP Headers, WSDL, 
WS-CDL or UDDI, but should be usable in any such "attachment" 
  - having a starting point is a good idea

There was less agreement between participants on the following points:
  - having a working group uniquely dedicated to develop use cases and 
  - the scope of working group in terms of the functionalities needed
  - the timeline
  - should the features and properties mechanism be used?

The W3C will take these recommendations into account when considering 
future work in this area.



Mark Nottingham and Philippe Le Hégaret, Chairs

Mark Nottingham   Principal Technologist
Office of the CTO   BEA Systems

Received on Tuesday, 2 November 2004 18:57:05 UTC