Oracle, Sun Offer Messaging Spec to W3C

A consortium of IT companies has put its weight behind a new specification
it hopes will improve the way messages are sent between Web services
platforms.

The WS-MessageDelivery specification 1.0 has been submitted to the World Wide
Web Consortium (W3C), which will now consider giving it a stamp of approval.

A bevy of companies including Oracle, Sun
Microsystems, Hitachi, Nokia, Arjuna Technologies, Enigmatec Corporation, IONA Technologies,
SeeBeyond, and Sonic Software helped author the specification.

The group
suggested the API set will make it easier to build complex
applications using Web services because it
standardizes the way Web service endpoints are referenced when multiple Web
services used in common exchange patterns.

The bid is similar to the WS-Addressing proposal submitted by BEA, IBM, and Microsoft . Without
officially giving its endorsement, however, a W3C staff comment suggests
WS-MessageDelivery may win out in the end.

“While addressing the same scope as the WS-Addressing document,
WS-MessageDelivery is more fully integrated with WSDL, by defining its
relations with the WSDL Message Exchange Patterns or by introducing a WSMD
description for WSDL,” the W3C said in its report.

The W3C was also pleased that WS-MessageDelivery follows the
current work of the W3C Web Services Description Working Group, and the
service references introduced in Web Services Description Language (WSDL)
2.0.

“WS-Addressing, while relying on the WSDL concepts, does not use the WSDL
service element as a service reference. WS-MessageDelivery relies on the
implicit open content model of WSDL for extensions, while WS-Addressing uses
an explicit extension mechanism (the reference properties),” the staff said
in its report.

“We’re making a level playing field for messaging,” Joe Keller, Sun vice
president Java Development Platforms, told internetnews.com. “You
already have this type of capability in an operating system. What this
specification does is extend Web services messaging to all systems.”

For example, the message exchange pattern enabled by WS-MessageDelivery
is the “callback pattern,” where one service sends a request to a second
service, but instead of waiting idly for a reply, continues doing other work
until notified that the second service has finished processing the request.
Prior to WS-MessageDelivery, messages would have to depend on proprietary
messaging structures, which limited how vendors were able to interoperate
and develop their products.

Keller said the group is welcoming additional contributions of Web services
specifications to open standards processes.

The W3 staff is recommending that work on WS-MessageDelivery should be developed in a separate
working group from those developing XMLP, WSD, or WS Choreography.