By Ronnie Julio Mohammad Alsawwaf

 Using more than two computer systems that are linked together  Handles a larger/more variable workload  Provides continued operation when/if one system fails  A main idea of clustering is that the cluster can appear to be a single system capable of a maximum workload

 Cluster computing can be used as a relatively low-cost form of parallel processing for scientific and other applications that lend themselves to parallel operations. An early and well-known example was the Beowulf project in which a number of off-the-shelf PCs were used to form a cluster for scientific applications.

 Because each computer system could be a multiprocessor, linking just two together could result in an output of eight computers processing at once.  Uses of clustering include high availability and load balancing

 Distributes the workload across the cluster  Increases reliability through redundancy  Mediates communication within the cluster  The main reason clustering is used is for load balancing

 Load balancing allows for:  optimal resource usage  maximum throughput  minimal response time  lowered change of overloading  Provides fault tolerance  when one server fails, one or more servers are available  Used to control traffic on high-traffic websites  traffic is handled more quickly

 The load balancing service is usually provided by a dedicated program or hardware device (such as a multilayer switch or a DNS server).

 PC Magazine (pcmag.com)   What Is It (whatitis.com)  Wikipedia