But Sun and its partners have yet to say to which standards body they will submit their proposed spec.
Arjuna Technologies, Fujitsu Software, Iona Technologies, Oracle, and Sun have teamed up to propose that individual Web services be called up and combined to form "composite applications." Through Sun's proposed set of standards, such a composite application would be given a shared runtime environment that could determine the specific systems contributing to the service. It also would be given a coordination agent that made sure applications ran in the correct sequence and a transaction manager that supervised transactions across dissimilar applications.
The proposed set is called Web Services-Composite Application Framework, or WS-CAF. Today's leading Web services handle such coordination issues is "in a very ad hoc manner, if at all," says Mark Little, chief team architect for Arjuna.
The proposed standards will take the guesswork and ambiguities out of how to coordinate services from scattered systems into one composite application, or new Web service, says Ed Julson, Sun's group manager of Web services standards and technology.
The alternative, Julson says, is to go forward with competing methods of resolving service issues, as is the case with two of today's Web-services security standards: Web Services-Security proposed by IBM, Microsoft and VeriSign, and Web Services-Reliability proposed by Fujitsu, Hitachi, NEC, Oracle, Sonic Software, and Sun.
Among the standards bodies that might receive the Sun proposal are the Oasis Open consortium of vendors setting XML standards; the World Wide Web Consortium; and the Internet Engineering Task Force. "From a pure technology standpoint, the group isn't breaking new ground," says Stephen O'Grady of Red Monk, a market research group. Sun and partners are making use of existing technologies, sometimes already in use in deployed Web services, he says. But "it's a novel and unique approach for creating composite applications composed of distinct Web services."
The most significant part of the proposal may prove to be the way it defines a way to manage transactions in the Web-services context, O'Grady says.
The Sun and partners proposal consists of three parts:
"There will be built-in interoperability issues as soon as developers start to build applications composed of several Web services," said Sun's Julson.
The proposed standards recognize existing Simple Object Access Protocol and WSDL, used to establish most of today's standalone Web services. Says Eric Newcomer, chief technology officer at Iona, "The big benefit of using these standards will be to use services from different sources and combine them together."