The recent advances in high-speed networks and improved microprocessor performance are making clusters or networks of workstations an appealing vehicle for cost effective parallel computing. Clusters built using commodity hardware and software components are playing a major role in redefining the concept of supercomputing.
A cluster is a type of parallel or distributed processing system, which consists of a collection of interconnected stand-alone computers cooperatively working together as a single, integrated computing resource.
This cluster of computers shares common network characteristics like the same namespace and it is available to other computers on the network as a single resource. These computers are linked together using high-speed network interfaces between themselves and the actual binding together of the all the individual computers in the cluster is performed by the operating system and the software used.
It's a kind of high-performance massively parallel computer built primarily out of commodity hardware components, running a free-software operating system like Linux or Free BSD, interconnected by a private high-speed network.
Motivation For Clustering
High cost of 'traditional' High Performance Computing.
Clustering using Commercial Off The Shelf (COTS) is way cheaper than buying specialized machines for computing. Cluster computing has emerged as a result of the convergence of several trends, including the availability of inexpensive high performance microprocessors and high-speed networks, and the development of standard software tools for high performance distributed computing.
Increased need for High Performance Computing
As processing power becomes available, applications which require enormous amount of processing, like weather modeling are becoming more common place requiring the high performance computing provided by Clusters