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December 7, 1998

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Illustration by
August Stein

J. Crew developed its own middleware to manage the process, but it's an approach Hansen wouldn't recommend. Packaged Web application servers from Netscape, Sun, and others come with pre-built objects that make it easier to deploy Web apps quickly. "Clearly, that's the way to go," Hansen says.

J. Crew is evaluating Web applications servers. A Web application server is different from an HTTP server, which receives requests for Web pages from browsers and serves the pages to the browsers. In general, Web app servers are used behind HTTP servers and don't serve pages directly to browsers.

Follow The Money
One of the Web's largest financial services Web sites is GetSmart.com. Like J. Crew's, GetSmart.com's online business has mushroomed. In 1996, the site processed an average of 2,000 credit-card applications a month. When the site added regional mortgages the following year, monthly volume leapt to 10,000 applications. This August, volume reached 50,000 applications after the launch of a national mortgage program, student loans, and auto loans. The site receives more than 1 million visitors a month.

GetSmart.com runs Sun's NetDynamics software and Netscape's Enterprise Server software together on Sun's Enterprise hardware, with an Oracle database on a separate Enterprise machine. GetSmart.com captures data from every click a user makes, including the last Web site visited, the user's browser model, and loan-application data the user has entered.

The NetDynamics server comes with objects that automatically maintain session state, carrying information from a user's previous transactions to the next. It also provides objects that encrypt information users submit. GetSmart.com used those objects to develop its Web site quickly. "It was the reduced development time that made us go to NetDynamics," says Uday Walia, the site's chief technology officer. "We don't have to spend programmer time on session state and security issues."

The NetDynamics software also improves the site's performance. Before deploying NetDynamics, GetSmart.com used CGI scripts. "CGI is very resource-intensive," Walia says. "Because NetDynamics uses less resources and works at the API level with Netscape Enterprise Server, it enables us to maintain very high speed and response times."

Travelocity started designing its site in 1995, before commercial Web application servers were available, and it plans to continue using custom middleware to connect its Web servers to Sabre Group Inc.'s mainframe-based travel reservation system. So far, it hasn't found anything better. "We've stayed with our software because we've gotten very good at understanding our bottlenecks and capacity issues," says Geiger.

Travelocity's middleware runs on an array of Silicon Graphics' Origin 2000 Unix servers. Here's how it works: The middleware passes data between the Sabre reservation system and a group of Netscape Enterprise Web servers and Netscape Commerce servers, which also run on Silicon Graphics systems. The middleware converts commands from the Web servers, such as requests to see airline fares from Dallas to Boston, into Sabre queries and submits them to the mainframe. When Sabre returns mainframe data, the middleware converts it into generalized data streams, a form of structured data. Then it converts the data from the generalized data streams into Web pages and passes it to the Web servers.

The middleware allows Travelocity to keep its Web site separate from the Sabre system, both of which are owned by American Airlines' parent company, AMR. It's a strategy that makes good business sense, says Steve Robins, an analyst at the Yankee Group. "Instead of forcing everything onto the legacy system, they have a certain amount of autonomy and nimbleness on the Web side," Robins says. "The Web people can make decisions without consulting the legacy side."

RealSelect Inc. used Microsoft's Distributed Component Object Model to upgrade its popular Realtor.com Web site earlier this year. The site runs on 20 PC servers, which range from single-processor to four-way machines running on Intel Xeon chips. The site is divided into three software tiers: Web servers, business logic, and data.

Eric Greenberg

Realtor.com's developers rebuilt the site using DCOM objects deployed on Microsoft's Windows NT-based Transaction Server. The developers wrote the objects in Visual Basic, a language typically used for desktop applications. "A lot of people pooh-pooh NT and VB," says Eric Greenberg, chairman and founder of Scient Corp., the integrator that rebuilt Realtor. com along with RealSelect. "This project validates that VB can be used to build a highly transactional Web site."

Scient and RealSelect, which updates the site frequently, chose VB for easy maintenance. "We designed an architecture that would use as much of what RealSelect already had as possible and leverage their staff's skill set," says Bret Sommers, director of systems architecture at Scient.

Before the redesign, Realtor.com's pages were generated by remote procedure calls, which were written in C++ and ran on Microsoft's SQL Server database. Whenever RealSelect wanted to change the look of its site, C++ programmers had to alter the remote procedure calls. By writing DCOM objects that perform the same functions, RealSelect gave its Web page designers control over the site's look. The DCOM objects are called by Active Server Pages--Web pages based on a scripting model from Microsoft. Designers can change pages without changing DCOM objects.

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See sidebar stories, "Monster Board Scales Up," and "GeoCities Copes With Rapid Growth."

Illustration by August Stein
Photo by Alan Blaustein