Data exchange format is just too slow, some say. But there's debate over the best way to make Extensible Markup Language fly.
Staff Writer, CNET News.com
The technology known as Extensible Markup Language has become a nearly universal way to share information online. But there's a growing recognition that XML's benefits sometimes come with a price tag: sluggish performance.
That problem is now spawning efforts to speed up XML traffic. Proponents say a skinnier XML will boost the speed of everything from Internet commerce to data exchange between cell phones. But so far, there's no agreement on the technology to make that happen.
Here's the problem: Right now, the XML standard calls for information to be stored as text. That means that an XML document, such as a purchase order or a Web page, can be easily viewed by a person or "read" by a machine, either through widely available text editors or XML parsers.
But performance problems result from XML's tendency to create very large files. That's in part because XML formatting calls for each element within a document to be tagged with labels written out as text. What's more, XML-based protocols, called Web services, also generate a great deal of XML traffic.
"Not only is XML verbose, but it's extremely wasteful in how much space it needs to use for the amount of true data that it is sending," said Jeff Lamb, chief technology officer of Leader Technologies, which uses XML extensively in teleconferencing applications and believes that a change is needed.
The leading candidate to help alleviate XML's performance woes is a technology called binary XML, which calls for a new format that compresses XML transmissions.
Sun Microsystems has started an open-source Fast Infoset Project based on binary XML, and the standards body responsible for XML, the World Wide Web Consortium (WC3), has formed the Binary Characterization Working Group to consider putting XML in binary format.
On the face of it, compressing XML documents by using a different file format may seem like a reasonable way to address sluggish performance. But the very idea has many people—including an XML pioneer within Sun—worried that incompatible versions of XML will result.
"If I were world dictator, I'd put a kibosh on binary XML, and I'm quite confident that the people who are pushing for it would find another solution," said Tim Bray, who's both co-inventor of XML and an executive in Sun's software group.
"But as it is, these people think they're right and they're not stupid, so maybe they are right. Thus, let's hope that they play nice with standards bodies and provide that free open-source software," Bray said.
Putting the squeeze on XML
The Fast Infoset plan, which represents more than a year of work, proposes that XML documents get shrunk down into a binary format in order to speed up transmission of files over the Internet. Sun has chosen a compression method that's already a standard used in the telecommunications industry.
The Sun engineers behind Fast Infoset argue that binary encoding is necessary because it can greatly improve performance, which is necessary in certain situations.