Types of clusters

When I think of clustering, I tend to classify clusters in three types, high availability, load balancing, and high performance computing.

• High Availability: No one wants any services they offer to be unreachable, especially since that downtime will almost undoubtably cost them money. High availability clusters offers the solution to this need for a lack of downtime.
• Load Balancing: Load balancing is almost a special subset of the high availability. The idea is to create a set up where you have multiple systems all serving the same service at the same time because the demand for the service is more than a single server can handle.
• High Performance Computing: Also known as Beowulf clusters, the idea here is to hook a bunch of regular computers up to act in a coordinated way so that they can do calculations or jobs that are bigger than any single computer. In this way, you can build a supercomputer using Commodity Off The Shelf (COTS) hardware. These systems do everything from calculating the origins of the universe to modeling weather to rendering movie special effects.