Server Cluster is composed of two or more than two independent servers, interconnected in a way that it appears as one server. A server cluster is basically used for providing high availability and scalability to the clients. The components of cluster are connected through a local area network, and each node runs its own operating system. Clusters are deployed to achieve high performance, reliability, and availability.
The major benefits of Server Clustering are its low cost, elasticity to add/remove resources as per the workloads, and enhance the speed and efficiency. A server cluster can be two node system having two personal computers connected, or can be an expeditious supercomputer.
The TOP 500 organization's semiannual list of the 500 fastest supercomputers includes various clusters, such as. The world's fastest machine in 2011 was the K computer which has a distributed memory, cluster architecture (1).
Server clusters are designed for the applications that have recently updated data or have high memory utilization. File servers, database servers, print servers, and messaging servers are few of the uses of server cluster. Message Passing Interface (MPI) and Parallel Virtual Machine (PVM) are the widely used methods for server communication. When one server in a cluster gets failed, data is disseminated to other nodes in the cluster, ensuring consistent access to the desired resources.