XAML: More Alphabet Soup for the Developer's Soul
Just when you have gotten comfortable with the alphabet soup ofUDDI, SOAP, ebXML, tpaML, vendors are throwing some new initials into the mix.Five vendors -- Bowstreet, Hewlett-Packard, IBM, Oracle, and Sun -- announced anew standard targeted at the budding Web services arena. The initiative, calledTransaction Authority Markup Language, or XAML, is an XML-based standard thatwill help businesses expose transactional capabilities through their Webservices, and to mix and match calls to multiple Web services.
As more vendors adopt or endorse the Web services model -- fromMicrosoft's .NET to HP's e-Services and e-Speak -- there is a pressing need toprovide low-level capabilities for organizations to access and transact withoutside systems.
XAML will enable companies engaging in business-to-businesstransactions to integrate and leverage existing transaction systems, as well asparticipate in new types of transactions. These interactions are being dubbedbusiness Web transaction processing, or BWTP, and is being distinguished fromOLTP. OLTP is based on internal systems, but BWTP transactions may invokelow-level Web services from multiple organizations on the Web.
XAML also is intended to tie together two groups ofbusiness-to-business standards. One group consists of emerging standards forWeb services, such as SOAP, ebXML, XP, UDDI, e-Speak, and WSDL. The secondgroup consists of existing transaction management standards, including XA andJTA.
"Companies are beginning the process of exposing andcombining their services on the Internet," says David Smith, vicepresident and research area director at GartnerGroup. "As these Webservices interactions mature, the need to ensure the integrity of theircustomers' transactions becomes more important. With broad industry support,efforts such as XAML could make all the difference between a robust and orderlyNet marketplace and one where buyers and sellers spend most of their timeresolving fouled transactions offline."
For example, a manufacturer may need to electronically purchase adirect material, such as a chemical product, to produce its finished goods. Asthe company selects the product from an electronic marketplace, it will alsospecify the required terms of the purchase, such as shipping availability anddelivery options, payment financing, casualty insurance, and governmentalcompliance for safe transport. All of these interrelated requirements need tobe satisfied prior to a purchase transaction being finalized. This scenariorequires coordinated processing of transaction-supporting Web services betweenthe chemical provider's inventory system and external services supplyingshipping insurance, financing, and transport. Should one of these services failto commit its operation, XAML provides the protocol that allows themanufacturer to send its requirements to other Web services to cancel,compensate, or find alternative actions.
Gartner's Smith warns that very few companies are currently doingtrue business-to-business e-commerce because of the complexity of dealing withmultiple partners with multiple applications and formats. Standards don't existyet to bring together billing, catalogs, and taxonomy, he adds. "The HolyGrail is to be able to plug all these pieces together, plug and play, withoutany integration work," he notes. Externally focused Web services may helpmake e-business more of a reality, he adds. Many vendors have begun toarticulate this vision as well, Smith says. Along with Microsoft, HP, and IBM,"many other vendors -- big and small -- bear watching, as the infrastructureis just beginning to take shape for e-services."
Notably absent from this latest consortium is Microsoft. WhileRedmond was not part of this first-round announcement, XAML proponents say thestandard readily supports all major layers of the software giant's BizTalk/.NETinitiatives, including registries (UDDI), business modeling languages (XLANG),service descriptions (WSDL), and transport/packaging/messaging (SOAP).
The XAML proposal will be submitted to one or several standardsbodies, which could include the World Wide Web Consortium, OASIS, and IETF. Thetarget date for submission to a standards body is Jan 15, 2001. At this time,the XAML group has not determined which body is the most appropriate for XAML.
GartnerGroup Inc.,Stamford, Conn., www.gartner.com
XAML consortium, www.xaml.org