Gigantic clusters: where are they and what are they doing

Clusters are like skyscrapers: mammoth structures towering above their smaller counterparts, except that skyscrapers have longer lives. The race to build ever bigger clusters is on, largely driven by emerging scientific and engineering applications. Several research efforts are underway at various universities and US research laboratories. The author examines some of the largest clusters in the world, providing some recent news and opinions from the experts. A cluster is a collection of complete computers (nodes) interconnected by a high-speed network. Typically, each node is a workstation, PC, or symmetric multiprocessor (SMP). Cluster nodes work collectively as a single computing resource and fill the conventional role of using each node as an independent machine. A cluster computing system is a compromise between a massively parallel processing system and a distributed system. An MPP system node typically cannot serve as a standalone computer; a cluster node usually contains its own disk and a complete operating system, and therefore, also can handle interactive jobs. In a distributed system, nodes can serve only as individual resources while a cluster presents a single system image to the user.