Mainframe Shops Eye Web Services
Web services has an obvious place in legacy integrations, but you'll need to use caution—it's still early in the game.
Web services seem tailor-made for large legacy IT shopsparticularly because they provide the ability to wrap COBOL or other legacy code and expose it as a Web service. Some are already using early versions to deliver legacy data to Web users.
But remember, Web services are still in the infant-to-toddler stages. Ultimately, just about any mainframe or host-centric application will be fair game for Web services. "This includes applications that are under the control of mainframe transactions managersCICS and IMS," according to Dietmar Kuebler, senior software engineer for IBM. Mainframe environments also offer plenty of advantages over other server platforms, including a key one, high scalability. "The number of potential users for a Web service often cannot be determined when the service is started," Kuebler says. Mainframes are also ideal for Web-services providers, because these systems can operate 24x7.
One major southern university recently passed up a Web-to-host or integration approach in favor of a Web-services architecture that enables students and employees to access XML-enabled data from three mainframes. "We looked at host-based emulators or screen-scrapers," says the university's IT director. "It was just absolutely, utterly too slow based on performance." With Web services, a middleware messaging server on the mainframe communicates with mainframe applications and converts data to XML. The XML information is merged with a style sheet and sent to a presentation screen on the Web.
Some mainframe shops are finding that Web services are a way to get around more complicated or proprietary middleware arrangements. Hewitt Associates, an HR and benefits consulting firm, recently rolled out a Web-services infrastructure to extend benefits data residing on its IBM z/OS Parallel Sysplex mainframe to employees at customer sites, as well as third-party information providers. Open standards such as HTTP and XML have replaced Hewitt's custom-built proprietary connectivity solutions to address front-end requests, says Tim Hilgenberg, chief technology strategist for Hewitt. "Although we don't use SOAP, I view this as an early generation set of Web services."
An Evans Data Corp. study found that 52 percent of enterprise development managers have Web services underway. Aside from Java and XML, very few adopted key Web-services ingredients: SOAP, UDDI and WSDL.
"Web services give people an alternative to accessing information," warns Darcy Fowkes, an analyst with Aberdeen Group. "Web services won't replace legacy integration, or a lot of the heavy lifting and deep integration that other integration solutions can provide. The trouble is, all this attention on Web services may slow down other legacy extension plans."
Security and authentication issues also trouble IT executives. "The risk is a lot of these standards aren't completely fleshed out by the W3C [standards committee] yetespecially the ones involving security," says the university IT director, who is employing standard SSL and encryption to mitigate the online risks.
Web services represent a promising new tool IT executives can leverage to extend host data and applications to Web-based end users. However, it will take time before we have a complete picture as to where and how Web services will best fit into the enterprise integration puzzle.
Joseph McKendrick is an independent consultant and author, specializing in surveys, technology research, and white papers.