SAR / RAR

Introduction to parallel & distributed algorithms by Carl Burch is available under a Creative Commons Attribution- ShareAlike 3.0 United States license. 1.2. Distributed computing A distributed system is one in which the processors are less strongly connected. A typical distributed system consists of many independent computers in the same room, attached via network connections.

Such an arrangement is often called a cluster .

In a distributed system, each processor has its own independent memory. This precludes using shared memory for communicating. Processors instead communicate by send ing messages. In a cluster, these messages are sent via the network. Though message passing is much slower than shared memory, it scales better for many processors, and it is cheaper. Plus programming such a system is arguably easier than programming for a shared -memory system, since the synchronization involved in waiting to receive a message is more intuitive. Thus, most large systems today use message passing for interprocessor communication. 1