Server clusters

When deploying large systems over a wide area to improve reliability, availability, and performance, computers are combined into a single cluster. What does a cluster mean? A cluster is several computers connected into a single computing center via communication channels, representing a unified computing resource from the user's perspective. Thus, a server cluster is a collection of computers linked together to perform unified computational tasks. In other words, server clustering allows computers to be combined into a single system to enhance computation speed, reliability, and system availability.

Server Cluster Capabilities

• The ability to operate on multiple or a single physical machine (combining virtual working servers);
• The ability for one or several processes to handle client connections within the cluster;
• The ability to connect new clients to processes inside the cluster, based on workload analysis of working processes;
• The ability to run processes in a computer cluster either as applications or as services.

As we can see, server clustering provides broad opportunities for system construction.

Cluster System Models

• Using a single central server for storing information, which provides greater fault tolerance in case of failures on individual cluster servers. However, with a large number of units in the computing system, performance dips may occur;
• A model of independent servers and their peripherals. In case of a failure of one system element, tasks are redistributed among the others with minimal performance loss. However, accessing a unified database becomes more complex.

Thus, it is possible to choose the most suitable model for your specific tasks and requirements.

Purpose of a Server Cluster

Depending on the tasks being solved, a cluster system is built using different solutions and principles. Therefore, different software products are used to create server clusters for various purposes. Correct selection requires classifying server clusters according to the tasks they perform.

Types of Server Clusters

• Load Balancing Cluster: Load balancing is the process of distributing or, more precisely, clustering databases across multiple servers to distribute the load and increase application performance and client access. Combining servers in a cluster for load distribution is designed not so much to speed up code execution but to distribute workload among several computers with identical applications. Thus, the application runs on a group of computers, whose power is effectively summed without losses.
• High Availability Cluster: Used when a task cannot be parallelized but must be reliably executed across multiple servers. This is also called server mirroring. High availability clusters ensure the application runs on any node in the unified cluster system, with nodes connected via data transmission systems for exchange and cloning. In case of failure of one cluster server, another takes over its function. Additionally, clients can connect to the nearest cluster server to reduce latency.

Thus, server clusters can be divided into fault-tolerant clusters, load balancing clusters, and computing clusters. This classification should be considered when selecting hardware and software for building a cluster.

To select the right cluster for your business, contact XServer. We use VMware-certified equipment from Dell and HPE, as well as hardware storage systems, so renting server equipment from us is reliable and cost-effective!