page_title: Computer cluster
section_title: Data sharing
hierarchical_section_title: Computer cluster / Data sharing and communication / Data sharing
caption_attribution_description: English: The new Nehalem cluster Deutsch: Der neue Nehalem-Cluster
context_page_description: A computer cluster is a set of loosely or tightly connected computers that work together so that, in many respects, they can be viewed as a single system. Unlike grid computers, computer clusters have each node set to perform the same task, controlled and scheduled by software.
  The components of a cluster are usually connected to each other through fast local area networks, with each node running its own instance of an operating system. In most circumstances, all of the nodes use the same hardware and the same operating system, although in some setups, different operating systems can be used on each computer, or different hardware.
  Clusters are usually deployed to improve performance and availability over that of a single computer, while typically being much more cost-effective than single computers of comparable speed or availability.
  Computer clusters emerged as a result of convergence of a number of computing trends including the availability of low-cost microprocessors, high-speed networks, and software for high-performance distributed computing.
context_section_description: As the computer clusters were appearing during the 1980s, so were supercomputers. One of the elements that distinguished the three classes at that time was that the early supercomputers relied on shared memory. To date clusters do not typically use physically shared memory, while many supercomputer architectures have also abandoned it.
  However, the use of a clustered file system is essential in modern computer clusters. Examples include the IBM General Parallel File System, Microsoft's Cluster Shared Volumes or the Oracle Cluster File System.
caption: A NEC Nehalem cluster
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