What Is Server Clustering and How Does It Work?

A server cluster is a group of servers, or nodes, managed under a single IP address, each with its own storage, memory, and processing power. By combining multiple servers, clustering enhances availability and reduces downtime by distributing workloads across nodes. If one server fails, another can take over, keeping the system running smoothly.

Downtime can lead to productivity loss, revenue decline, and damage to reputation. Server clusters minimise this risk by ensuring system accessibility even in the event of hardware failure. They also improve performance, handling large volumes of requests efficiently. Read on as we explore the key features, types, and benefits of server clustering.

Features of Server Clusters

Here are some of the key features that define server clustering:

1. High Availability  

Server clusters are well-suited for high-traffic websites like online stores due to their high availability, which makes them ideal for load balancing. They have multiple hosts that can take over if a server overloads or shuts down. 

2. Load Balancing 

Load balancing is the key feature of cluster servers. Server clusters can balance multiple requests across a set of active nodes, speeding up operations and allowing the workload to be distributed well. Separate functions and kinds of workloads can be allocated to different servers. The load-balancing software allocates different requests to different servers using an algorithm.

Load-balancing clusters are often used for telecommunications companies and data centres. 

3. High Performance 

Also known as supercomputers, these clusters have high capacity and comprise multiple computers connected to a common network. Many such clusters can be connected to a common data storage centre to process data quickly, which is helpful for high-speed performance and data transfer.

Such clusters are usually used for Internet of Things (IoT) and artificial intelligence (AI) technology. They power tasks like live streaming, finance, research, and other operations. 

Types of Server Clusters

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Server clusters can be categorised into three main types, depending on how the nodes are connected to the data storage system and how they function:

1. Single Quorum Cluster

This is the most prevalent type of cluster. It has multiple nodes with one or more cluster disk arrays that use a single connection device. The clusters are managed and owned by a single server, and each node is connected to a central bus.  

2. Majority Node Set Cluster

In this type of cluster, each node has its own copy of the cluster’s configuration data. This is well-suited to clusters where servers are situated across different geographical locations. Since each node has its own duplicate of the quorum data, there is no shared storage device. 

3.  Single Node Cluster 

This type of cluster has a single node and is often used for testing and R&D for cluster applications. However, it is rarely used outside of testing and research because its use is very limited due to the lack of failover protection. The failure of one node upsets the whole cluster. 

How Does Server Clustering Work? 

Each cluster server has its own memory (RAM), storage, and processing (CPU). 

Usually, all the nodes don’t function at the same time. One node will operate while the others are on standby. If the active node fails to handle the traffic or performs a server request, the cluster will redirect the request to another node. This transfer of excess workload to another node is known as load balancing. The load balancing helps prevent downtime. 

Load balancing can be done through an active-active or active-passive setup. An active-active cluster means that all the nodes work at the same time to manage the load. An active-passive cluster relies on a primary node to handle the load with a secondary node on standby to prevent downtime. 

Usually, a single node is operational while others are on standby. If the active node is unable to serve a request, then the cluster redirects the load to other nodes. 

The prompt handover is possible because the nodes share a storage system, which is known as a quorum. The quorum carries information about the server cluster and tracks changes. 

Benefits of Server Clustering

Here are the most prominent benefits of server clustering:

1. Scalable: Clustering allows you to scale easily to handle higher resource demand. With multiple servers and clustering benefits, you can easily improve flexibility and scalability. It’s easy to add another node to increase the capacities of the server.  
2. Improved Availability: Server clusters improve availability since you can redirect user requests to different nodes if one is busy. This also allows more people to use a website at the same time.
3. Reduced Costs: A server cluster helps reduce costs by reducing downtime and preventing the website from losing traffic and potential customers.
4. Customisable Infrastructure: Clustering servers allow you to assign separate workloads to separate servers and optimise processes. You can also customise the number of servers to ensure that the infrastructure is designed for the workload. 
5. Failover Protection: This is essential because it prevents server downtime and data loss. In other words, it allows services to continue even if one of the nodes fails. In case a node fails, another node immediately takes over so that the user doesn’t realise there has been a failure. This helps maintain customer satisfaction and protects against revenue loss. 
6. Improved Performance: Cluster servers enhance performance by ensuring continuous uptime and speeding up processes. They can offload specific tasks, like database-related operations, to specialised servers, improving the overall speed of websites or applications. Clustering also protects against failures, including application errors, hardware malfunctions, and site-wide issues like data centre outages.

Overall, server clustering offers a robust solution for businesses seeking scalability, improved availability, and optimised performance. By enabling seamless failover protection and customisable infrastructure, server clusters reduce costs and prevent downtime, ensuring a smooth user experience.

Whether you’re managing high traffic, handling large workloads, or safeguarding critical operations, clustering provides the flexibility and reliability needed to keep your systems running efficiently.

Summing Up 

Server clusters help improve availability and speed up performance. They work through load balancing and redirecting requests to other nodes when a node is busy. The three types of server clusters are a single quorum, a majority node set, and a single node. They provide failover protection, reduce costs, and enable scalability and customised infrastructure. 

In this regard, Digital Pacific provides a range of tailored website solutions to meet the unique needs of your industry, whether you’re in architecture, advertising, law, or beyond. Our server clustering options ensure high availability, improved performance, and scalability to keep your business running smoothly. 

Explore our plans today and let Digital Pacific support your success with the perfect solution for your needs.