Tux Makes Orbitz Fly High - page 2
Lofty Goals Reached by Linux
The Orbitz web application servers originally ran on 168 Sun Enterprise 4500 application servers. Last fall Orbitz migrated its web applications over to 100 Intel-based Linux Compaq servers.
The decision to use Linux for the Orbitz search engines came down to two major areas of concern. One was cost and the other was the ability to scale the systems horizontally, on the fly, as demand and needs grew. Another contributing factor was that Orbitz wanted to be one of the top 20 Web sites on the Internet. That was only possible by keeping costs in line while achieving maximum speed and reliability.
The move to Linux certainly has pushed Orbitz towards this lofty goal. As described by Leon Chism, Orbitz' Chief Internet Architect, "we have twice the capacity at one tenth the cost." Chism ought to know what he's talking about with a decade of leading design and development of highly scaled mission-critical systems for Zefer and Andersen Consulting.
Chism's opinion of the migration process was bubbling with enthusiasm: "it was a great experience moving from Sun to Linux... It was a breeze," he said.
The machines used for the search engines and web application servers are now all commodity 1U dual processor Compaqs with 2 GB of RAM. Chism didn't recall the typical disk size, but did say that many of the low-fare search engine machines (which were always Linux) run diskless. Disks are not needed because these machines simply sift through mountains of data. Lots of sorting, not much disk activity. When data needs to go to disk, it's shipped via NFS. Running the low fare machines diskless also made the situation better in another area: lowered electrical power consumption in the data center was a major benefit.
Sun had some influence in the choice of Java as the programming language for the Orbitz system. Chism added that the systems were not really clustered. He described it more as "load balanced." Jini Network Technology software, which is built on top of the Java infrastructure made it possible to add or remove machines, services, and applications without affecting the overall performance of the system. "Customers don't even notice if a machine goes down or is pulled out of service," Chism explained.