A cluster can be defined as a system where two or more computers work jointly to perform heavy processing or mission-critical tasks. Basically, any kind of critical application, or applications that cannot stop working or cannot lose data (such as core banking systems, for example) can use the cluster technology.
High Availability: Cluster model is configured to provide an availability of services and resources on an ongoing basis through the use of redundant systems. The general idea is that if one web server in the cluster fails, applications or services may be available on another server. This type of cluster is used for data base of mission critical e-mail, file servers and applications.
Load Balancing: This model distributes incoming traffic or resource requirements on all servers in the cluster. All servers are responsible for monitoring requests and if a server fails, requests are redistributed among the available servers at the moment. This type of solution is usually used in the application servers.
High Availability Load Balancing: As the name suggests, this is a sport that combines features of both types of cluster, thus increasing the availability and scalability of services and resources. This type of cluster configuration is widely used in application servers, web and e-mail.
Main Advantages of the Cluster:
- High performance;
- High availability;
- Better utilization of server capacity;
- Use of lower-cost servers.