When immigrants landed on New York’s Ellis Island in the 19th and early 20th centuries, record-keeping consisted primarily of scribbling a few notes into a big book. Today, The Statue of Liberty-Ellis Island Foundation requires powerful computer technology to store and present some 25 million individual records and 3.5 million related images.

Like a growing number of enterprises, the foundation has discovered that clustering?the practice of connecting two or more computers together in such a way that they behave as a single computer?is the answer to its massive data management requirements. Clustering technology, which is used for functions such as load balancing, fault tolerance, high availability and high-performance computing, has been available for several years. Now, the interrelated lures of enhanced performance and lower cost?made possible by new software and hardware technologies?are encouraging a growing number of enterprises of all sizes to look into clustering technology. The number of new clustered servers installed worldwide is projected to increase from nearly 772,000 in 2002 to around 1.8 million in 2007, according to Gartner.

Reasons to Be Popular

Clustering offers a variety of advantages over other system architectures for a variety of tasks. And no single issue is driving clustering’s rising popularity, says Nathaniel Palmer, vice president and chief analyst at Delphi Group, a Boston-based IT consulting and research company. "There are several different trends, ranging from how computers are built to the emergence of new software standards," he says.

Other analysts agree. "Web services development, the shift toward scaling out at the edge server level and in business logic servers, and the emergence of new blade server systems will drive up the use of clustering," says Jamie Gruener, a senior enterprise computing and networking analyst at the Yankee Group, a Boston-based technology research firm. Add the fact that major hardware vendors?including Dell, Hewlett-Packard and IBM?are aggressively promoting clustering, and it’s no surprise that the technology’s profile is rising rapidly.

It’s also quite easy to make a solid business case for a move to clustering. In an IT world where data consistency, availability and reliability are paramount, the redundancy of clustering can’t be matched by standalone systems?or even multiple machines.

The Cluster Migration

For Sam Daniel, The Statue of Liberty-Ellis Island Foundation’s IT director, clustering proved to be the most affordable answer for powering an extensive 100GB database and a website that can receive as many as 8 million requests per second (which can happen, for example, when the site gets television publicity). "It would have been more expensive to get one huge server to handle all these types of queries coming to our site," says Daniel, who adds that clustering also allows for cheaper and easier scalability. "By putting in a cluster system, we could add in several less costly servers as the need arises." Daniel estimates that the hardware, software and maintenance makes the cluster at least 30 percent less expensive than acquiring and operating a large, standalone server.