Q. General use of cluster computing?

A general use of cluster computing is to balance traffic load on high-traffic web sites. In web operation a web page request is transmitted to a manager server that then decides which of the various identical or very similar web servers to forward request to for handling. The exploit of cluster computing makes this web traffic uniform. 

Clustering has been available ever since 1980s when it was used in DEC's VMS systems. IBM's SYSLEX is cluster approach for mainframe system. Sun Microsystems, Microsoft and other leading hardware and software companies provide clustering packages for scalability as well as availability. As traffic or availability assurance raises all or a number of parts of cluster can be raised in number or size. Cluster computing can be used as a relatively low-cost form of parallel processing for scientific and other applications too which lend themselves to parallel operations An early and in addition well-known illustration was project in which some off-the-shelf PCs were used to form a cluster for scientific applications.