Sabre Rebuilds on the Fly

Sabre is more than four years into a project of migrating its massive Air Travel Shopping Engine and Low Fare Lookup application from its Hitachi mainframe legacy system onto a platform anchored by HP's NonStop architecture and a farm of commodity servers

It was about 10 years ago when executives at Sabre Holdings Corp. decided they needed to start thinking about moving their online travel business off their existing proprietary mainframes and onto a new platform.

Internet-based travel booking was gaining rapid acceptance among a growing group of computer-literate consumers and among travel agents and airlines, and with that grew the need for real-time data. Travelers were demanding more services and more options, and those demands were driving up costs for the worldwide travel commerce company. Sabre needed an infrastructure that was cheaper, faster, easier and more scalable.

Fast-forward to 2004, and Sabre is more than four years into a project of migrating its massive Air Travel Shopping Engine, or ATSE, and Low Fare Lookup application from its Hitachi Ltd. mainframe legacy system onto a platform anchored by Hewlett-Packard Co.s NonStop architecture and a farm of commodity servers running Linux.

"We knew that for our evolution, revolution and existence, we had to continue to push our technology further," said Craig Murphy, chief technology officer at Sabre, who inherited the project when he joined the company in 1996.

Sabre first appeared on the travel scene in 1960, when it installed the first computerized reservation system. Since then, the $2.05 billion Southlake, Texas, company—which has about 6,500 employees in 45 countries—has grown to include four business units, including the online reservation site and GetThere, a corporate travel reservation system.

In 2002, Travelocity, a key part of Sabres ATSE, garnered about $359 million in revenue and $3.9 billion in gross bookings and accounted for about 14 percent of Sabres revenues. That figure was expected to grow to about 19 percent for 2003.

Sabre officials said the company has more transactions per second running through its computer systems than does the New York Stock Exchange. Its pricing application continuously updates 20 million fare and rule records and 1.5 million schedules.

Sabre executives entered the project to move its applications—from dynamic scheduling and search to rule validation and pricing—off the legacy mainframe infrastructure housed in its Tulsa, Okla., data center with several goals in mind. They wanted to reduce their IT costs while increasing the scalability and flexibility of their systems. At the same time, they wanted to increase services to customers.

"Weve stated our technology goals as better, faster, cheaper," Murphy said. "Open-source tools, used appropriately, mean that we can actually deliver on all three goals instead of picking just one or two. The sheer volume, combined with the uptime expectations of our worldwide customer base, means that weve always been pushing the limits of any technology platform. ... Open systems are now moving up into the space that was previously only occupied by mainframes."

The project started in 2000 with a proof of concept with Compaq Computer Corp.—before its acquisition by HP in 2002—and its Himalaya NonStop platform, Murphy said. The goal was to find an architecture that offered the same reliance as the mainframes but at a fraction of the cost.

"We wanted to have the data rock-solid," he said. "We wanted to have the pricing rock-solid."

In 2002, Sabre got its first NonStop servers up and running and has grown the infrastructure over the past two years. Company administrators now run its ATSE platform on 17 S8600 NonStop servers, which they use as a fault-tolerant master database.

At the same time, the company runs its CPU- and memory-hungry Low Fare Lookup applications on 45 of HPs four-way rx5670 systems powered by Intel Corp.s 64-bit Itanium 2 processors, with 32GB of memory each and running Red Hat Inc.s Red Hat Enterprise Linux AS 3.0 Linux operating system and MySQL 4.0. Murphy said the number of servers could grow to 100 or more by the end of the year.

A key advantage of the NonStop servers, which run the proprietary NonStop Kernel operating system, is its POSIX compatibility layer, which enables IT administrators to run the same application source code as the Linux systems. It also supports C++, Java and SQL development using the POSIX interface, Murphy said.

More than 70 engineers have been involved in migrating the applications to the new infrastructure.

About two years ago, Sabre outsourced its data center operations to Electronic Data Systems Corp., a move that has helped further reduce the companys IT expenditures.

Initially, the migration was based on the Unix environment, but even as Sabre was making that migration, executives knew they wanted to bring Linux into the mix. The open operating system offered low cost, high flexibility and good scalability, Murphy said, and it fit into Sabres drive for an open system with distributed and standardized components.

"The technicians are energized and indeed electrified by Linux," Murphy said. "They want to work on it."

Last summer, Sabre began porting the Low Fare Lookup applications, which help users hunt for the lowest prices, onto the smaller HP servers running both Unix and Linux, he said. Now all the servers involved in the project are running Linux.

Whats evolved is a parallel architecture that has a cluster of NonStop servers running the key back-end jobs and transaction data, as well as a growing farm of Linux systems running the MySQL database and doing the jobs that require intense processor and memory work.

Tying all this together is GoldenGate Software Inc.s data synchronization software. The San Francisco companys software captures changes made in the database and immediately replicates it into the MySQL database on the servers running Unix and Linux. According to officials at GoldenGate, data is replicated on a continuous basis, with a standard batch transmission carrying a load of 300,000 updates an hour.

"Their origins are on NonStop, but they also support Unix and Linux," Murphy said.

Although the project is still under way, the results have been what executives had hoped for, he said. The new systems have given Sabre more flexibility and richer functions in their offering, from more dynamic pricing to better availability data. It also will result in a 40 percent reduction in the companys expenses, saving Sabre millions of dollars, Murphy said. That includes cutting the cost of the technology, increasing the productivity of the staff and reducing the number of people needed to run the operations.

"Were just being cheaper in the way were doing IT," he said.

For customers, the new technology will mean a greater number of options and better prices as they make their travel plans. About eight years ago, Sabre customers could see three options when planning a trip.

In the late 1990s, that figure grew to nine, and now users have 19 options. Next year, those options will number in the hundreds, involving everything from pricing and flight alternatives to more car rental, hotel and destination requests, Murphy said.

The technology has also allowed Sabre to increase the number of package deals it can offer.

"[Traveling] is a way of getting from point A to point B," Murphy said, adding that for Sabres customers, the questions are, "How many different ways are there? How many different prices are there?"

However, while Sabre is feeling the positive effects of the migration, the company is still at least two years away from completing the project. There are half a dozen project-related tasks under way, including completing the move to Linux and the continued implementation of the MySQL database.

There also is the chore of expanding the Travelocity specifics and getting all the applications up and running on the new infrastructure.

A key job will be to complete porting the applications, business logic and data onto the new systems, Murphy said.

But just as crucial, perhaps, will be to get the companys technicians to the point where they are as proficient on the open systems as they were on the legacy infrastructure. A key challenge in the project was changing the mind-set of IT administrators and developers, who were used to working in the legacy environment—working with flat files and developing legacy code—rather than in open systems, with their object-oriented base and C++ and Java development environments.

"Change is tough for anyone," Murphy said. Sabres engineers "have a high level of experience on the old [system] but are just learning the new."

Over the next year or so, Sabre also will have to shut down the legacy mainframe system, he said.

Despite the work that still needs to be done, Murphy said he is confident the project will be a success.

"Its a huge undertaking, and like any undertaking in IT, it can sometimes go off the rails," he said. "But I dont think well do that. I dont think we have any technical showstoppers. Im quite confident there."