e-Commerce Applications Using Oracle8i and Java from Scratch

Using Clusters to Improve Scalability

Clusters can exist in a variety of configurations:

• Tightly coupled systems use multiple CPUs that share memory through a common memory bus. Performance of such systems is limited by the bandwidth of the bus.

• Loosely coupled systems use a node that contains one or more CPUs and communicates with other nodes through a high-speed common bus. The nodes don't share memory, but they do share disk and other resources.

• Massively parallel processors are comprised of nodes that usually contain an inexpensive CPU. These systems achieve high scalability by making use of hundreds of nodes. The nodes communicate by using a high-speed interconnect. These systems are also referred to as shared-nothing architecture because neither ...