4) Clustered System –
A clustered system consist of several computer system connected through a network.
Cluster can also be used to providehigh performance computing requirement.
It is also a multiprocessor system which gether together multiple cpu.
Clustered system different form the multiprocessor system because they are composed of two or more individual system it is called loosely coupled.
Cluster computers share storage and are closely linked via local area network.
Clustering is usually used to provide high ability service – that is service will continue given if one or more systeem in the cluster fail.


There are two types of clustering –
A. Symmetric Clustering
B. Asymmetric Clustering

A.) Symmetric Clustering – In symmetric clustering two or more host are running application and are monitoring each other.
B.) Asymmetric Clustering – In Asymmetric Clustering one machine is in host stand by mode while other is running application.