Cluster Computing: A High-Performance Contender

W hen you first heard people speak of Piles of PCs, the first thing that came to mind may have been a cluttered computer room with processors, monitors, and snarls of cables all around. Collections of computers have undoubtedly become more sophisticated than in the early days of shared drives and modem connections. No matter what you call them—Clusters of Workstations (COW), Networks of Workstations (NOW), Workstation Clusters (WCs), Clusters of PCs (CoPs) —clusters of computers are now filling the processing niche once occupied by more powerful stand-alone machines. In its simplest form, the computers in your office that are connected to your local area network constitute a workstation cluster. In addition to the hardware, a workstation cluster also includes the middleware that allows the computers to act as a distributed or parallel system and the applications designed to run on it. While a system based on low-end workstations and network technologies may not at first seem particularly useful, such systems have been the testbeds for a new computing paradigm: high-performance and high-availability cluster computing. This class of system is becoming increasingly commonplace; in fact, most academic institutions and industries that use high-performance computing either already use or are thinking of using workstation clusters to run their most demanding applications. Even companies that can afford traditional supercomputers are becoming interested in commodity clusters. Why the switch? For some, cluster-based systems provide a way to stretch their computing dollars, allowing the reuse of seemingly obsolete office or classroom systems. Others have found that a cluster of high-performance workstations can easily compete with the best supercomputers IBM or SGI have to offer. A company can download a few tools from a public Web site and order a collection of machines and network equipment to put together an 8-Gflops system for around $50,000. Assembling a powerful supercomputer would cost around $200,000. A cluster consists of all the components found on any LAN with PCs or workstations: individual computers with their processors, memory, and disks; network Although many educational institutions teach undergraduate and graduate students about the hardware and software components that make up a cluster, few courses or programs concentrate on the wealth of technologies that constitute the complete cluster environment, from hardware to application development tools. In order to introduce cluster computing into the curricula of more college programs, the Task Force on Cluster Computing has set up a Web site, informative …