Heartbeat is a means of signaling nodes that the main node is still active. The need is more apparent on the High Availability (HA) cluster.Ī High Availability Cluster also may require an external storage device that all nodes have access to it. You can set the hostname to 'Node-1' and 'Node-2' if you wanted.įor very basic intentions, it is best to have these systems set up with two Network Interface Cards (NICs). So, in a two-cluster system, we have Node-1 and Node-2. Two systems are a very minimal cluster, but it does work.Įach system in a cluster is called a Node. Let’s say we have two systems working together. Since a cluster is a set of computers acting as one system, we must be able o understand the system as a whole. NOTE: The Distributed and Parallel Clusters are referred to as High Performance (HP) Clusters.īefore we get in too deep on the types, let’s break down the various components of a cluster. Parallel (Beowulf) – jobs are managed by multiple processors on multiple systems.Distributed – jobs will be managed by different systems.Load Balancing – balances the load between multiple systems when a service needs to be available to numerous systems at once (can be used for other three types of Clusters).High Availability (HA) – Used for Fault Tolerance to keep server services available to employees or customers.If you plan to deploy a cluster, you need to decide which cluster you are needing for your specific purpose. There are four types of clusters that we will discuss.Įach type of cluster has a different purpose. The idea is a very basic concept of clustering, but mostly correct.Ī cluster of computers is a group of systems acting as one for different purposes. When most people hear the word ‘cluster’ they may think that this is a group of computers acting as one system. I hope to cover a basic understanding of clustering as well as give you a way to demonstrate making a small virtual cluster.