"Every data center is evaluating some flavor of XML and many - I would say the majority - are actively using XML-enhanced software in production," says Sebastian Horst, senior editor of The Gilbane Report, a newsletter that covers content management technologies.
The question that remains, he says, is how deeply XML's roots penetrate most data centers. "I know of very few, if any, that have completely saturated their enterprise, so there is plenty of opportunity to expand the role and consequently the value of XML in the data center."
Some major companies are pushing the envelope, though. Deutsche Bank of New York City applied layers of XML to critical datasets that needed to be shared by different applications and servers. The company reportedly saved $2 million by using XML parsers, or transformation engines, to swap data between platforms.
"It's allowed the company to replace huge numbers of legacy systems that did nothing more than transform data (between formats)," says Peter Aiken, president of the Richmond, Va.-based Institute for Data Research, which consulted on the project.
Deutsche Bank also revamped its internal data center without ripping out every legacy system. Instead, systems gradually were pulled apart into component-based pieces, with XML parsers sending messages between servers. More significantly, the parsing technology helped catch, and change, transaction errors. That alone helped Deutsche double its online financial transactions to about 200,000 per day, Aiken says.
In contrast to Hypertext Markup Language (HTML), which is used to graphically depict data within Web browsers, XML uses special markup tags to define and describe data elements within a document. In other words, HTML tells what a data element looks like, whereas XML tells what it means.
XML coding aims to make application data more nimble. Most organizations have to manage hundreds of applications powered by brittle internal code. That means making changes to one application in a linked database creates unintended changes to other applications.
Data that breaks in one application triggers a chain reaction of breaks all along the system. Loading modified data into your human resources system, for example, may screw up payroll processing, which in turn affects how the company reports its number of full-time employees.
XML's chief advantage, says Aiken, is its ability to rapidly transform and share common data among different databases. "It turns out that 20% to 40% of all IT budgets is spent just on transforming data, shuffling it around from one format to another," he says.
Enterprises sometimes use XML to push applications to mobile workers using PDAs or other handheld devices. Imagine that your salesperson in the field needs to access a mainframe-hosted application via his cell phone. He won't want to sift through the same volume of information as someone accessing the data through a PC. XML-constructed browsers or style sheets could be used to send chunks of relevant data without sending the entire body of code.
"The true business value of XML is that you're extending the usefulness of your legacy applications," says Jess Thompson, a research analyst with Gartner, Inc. of Stamford, Conn. "But XML is like putting lipstick on a pig, because it doesn't change the architecture of the application to make the logic more useful. The logic within legacy applications represents a significant investment in intellectual property."
Nor does integrating XML into your data center guarantee cheaper operations, says Pat McGrew, a data center consultant and director of document solutions for Pitney Bowes Management Services). Migrating proprietary applications, including special in-house code and bridge patches, to a normalized XML infrastructure where internal and external applications interoperate without problems, actually can be quite costly. "This is where you learn what you don't know about your own data," says McGrew.
David Allen, the chief operating officer of IDR, which worked on Deutsche's XML integration, says data center managers should start small. Identify a segment of data that can be wrapped with XML tags, migrate the application-specific data, and test it. Don't worry about making changes, since XML transformation sheets are user-friendly enough to make rapid changes.
"We're not saying 'use XML everywhere and the world will be perfect.' But a judicious use of XML can help maintenance data transformations, data maintenance, and application and integration costs," he says.
