Almost all businesses rely on online services for critical business processes and revenue.
Downtime can result in lost productivity and revenue. Not to mention, performance disruptions may lead to reputation loss.
The real cost of outages, software failure, and outdated technology could mean millions.
The good news is you can avoid these failures by using server clusters in your infrastructure.
But what is server clustering?
What Is a Server Cluster?
A server cluster is a unified group of servers distributed and managed under a single IP address. This setup ensures higher availability, proper load balancing, and system scalability.
Each server is a node with its own storage (hard drive), memory (RAM), and processing (CPU) resources. For instance, a two-node cluster configuration means that if one physical server crashes, the second will immediately take over. This process, known as failover clustering, helps you avoid downtime.
Ideally, you use multiple web and app nodes to guarantee hardware redundancy. This kind of architecture is known as a high-availability cluster. It helps prevent downtime if a component fails.
This is especially true if the operating system fails, which does not have redundancy in a single server. Since there will be no site failures, your users will not even know that the server crashed.
There are two usual types of server clusters – manual and automatic. Manual clusters are not an ideal solution since the manual configuration of a node to the same data IP and address comes with downtime. Even a 2 to 5-minute downtime could be expensive or possibly critical. On the other hand, automatic clusters let you configure software ahead of time. This type of cluster setup automatically carries out the server switch.
Why Are Server Clusters Deployed?
Businesses often deploy a server cluster system to avoid downtime and maintain system accessibility, even when critical hardware fails. Cluster architecture is also ideal for businesses suffering from performance degradation. It lets them split off the database server to enable fast and uninterrupted performance for high-volume workloads.
What Are the Types of Server Clusters?
There are four types of server clusters. The type you choose depends on your business objectives and infrastructure needs.
1. High Availability (HA) Server Clusters
High availability (HA) clusters are an optimal choice for high-traffic websites. For example, you may use HA clusters for online shops or applications that need critical systems to remain operational for optimal, continuous performance.
High availability clusters let you avoid single points of failure since they are built on redundant hardware and software. They are critical for load balancing, system backups, and failover. They are composed of multiple hosts that can take over if a server shuts down. This guarantees minimal downtime if a server overloads or fails.
HA clusters have two architecture types: Active-Active and Active-Passive.
An active-active cluster means all nodes work simultaneously to balance loads. In contrast, an active-passive architecture means a primary node handles all workloads. Meanwhile, a secondary node remains on standby for downtime.
The secondary server is also known as a hot spare or a hot standby since it contains the database from the primary node. As the hot standby is ready to take over if a component crashes, this is a lower-cost implementation than active-active.
High-availability clusters give you more reliability while also letting you scale easily. Not to mention, they offer more efficient maintenance and robust infrastructure security. With these clusters, you can save costs, minimize downtime, and create a better user experience.
2. Load Balancing Clusters
Load Balancing cluster refers to a server farm that distributes user requests to multiple active nodes. The main benefits include accelerating operations, ensuring redundancy, and improving workload distribution.
Load balancing lets you separate functions and divide workloads between servers. This configuration helps maximize the utilization of resources. It uses load-balancing software to direct requests to different servers based on an algorithm. The software also handles outgoing responses.
Load balancers are used in the active-active configuration of a high-availability cluster. The HA cluster uses the load balancer to respond to different requests and distribute them to independent servers. The distribution can be symmetrical or asymmetrical depending on the configuration data and computer performance.
In an active-passive high-availability cluster, the load balancer monitors nodes’ availability. If a node shuts down, it doesn’t send any more traffic to it until it is fully operational.
Load balancing architecture also lets you use multiple links at the same time. This feature is especially useful in infrastructure that requires redundant communication. For example, this architecture is often deployed by telecommunications companies and data centers. The main benefits include cost reduction, high-bandwidth data transfer optimization, and better scalability.
3. High-Performance and Clustered Storage
High-performance clusters, also known as supercomputers, offer higher performance, capacity, and reliability. They are most often used by businesses with resource-intensive workloads.
A high-performance cluster is made up of many computers connected to the same network. And you can connect multiple such clusters to the data storage centers to process data quickly. In other words, you benefit from both high-performance clusters and data storage clusters and get seamless performance and high-speed data transfers.
These clusters are widely used with Internet of Things (IoT) and artificial intelligence (AI) technology. They process large amounts of data in real time to power projects such as live streaming, storm prediction, and patient diagnosis. For this reason, high-performance cluster applications are often used in research, media, and finance.
4. Clustered Storage
Clustered storage consists of at least two storage servers. They let you increase your system’s performance, node space input/output (I/O), and reliability.
Depending on business requirements and storage demands, you can opt for a tightly or loosely coupled architecture.
A tightly coupled architecture is directed at primary storage. It separates data into small blocks between nodes.
In contrast, a self-contained, loosely coupled architecture offers more flexibility. But it doesn’t store data across nodes. In a loosely coupled architecture, performance and capacity are limited to the capabilities of the node storing the data. Unlike tightly coupled architecture, you can’t scale with new nodes.
Benefits of Server Clustering
A clustered environment helps you manage hardware, application, and website failures. In other words, this environment ensures uptime and availability. By saving engineering efforts, it can drastically reduce costs associated with system recovery.
Put simply, investing in server clusters lets you save money in the long run.
Flexibility and Scalability
An individual server handles everything from the network connection to storage for a business. By deploying a multi-server architecture with clustering capabilities, you can significantly improve the flexibility and scalability of that server.
In other words, clustering lets you scale one server to handle the increasing resource demand. Not to mention, it's simpler for businesses to deploy an additional node to an existing cluster. If you have a managed dedicated server, you can do so with a simple phone call.
Improved Availability and Performance
Another motivation driving investment in cluster solutions is performance. Besides providing hardware redundancy and ensuring uptime, a clustered environment can improve performance.
In particular, a cluster with a dedicated database server can improve website or application speed. This setup lets you improve performance while increasing support for simultaneous connections.
If you comply with regulations such as PCI-DSS, server clusters become a practical necessity. This is especially relevant if you store financial information on a server that doesn't connect to the Internet.
Reduced IT Costs
Companies need a network with built-in redundancy to ensure that customers can always connect to it. Besides that, the servers need to act as a single system. A clustered environment helps with that by preventing downtime and actually lowering costs by keeping the server fully operational.
In other words, clustering lets you provide continuous uptime. As clustered servers are configured to work together on a single network, they reduce risk vulnerability while boosting network performance.
Clustered server architecture can benefit businesses of all sizes. Specifically, it helps optimize processes, from networking services to the end-user experience. All these workloads are assigned to applications, and they get rolled out on separate servers that sync in real time.
Specifically, a business can customize the number of servers in a clustered environment. This customization allows for cost management while eliminating single points of failure. Using custom-built infrastructure ensures your environment is specifically engineered for your workload.
A reputable service provider can help determine the most cost-effective architecture for you.
The True Cost of Downtime
According to Uptime Institute’s 2022 Outage Analysis Report, 80% of organizations report their data centers have experienced some outage over the past three years. For 60% of those outages, total financial losses were $100,000 or more. An unlucky 15% of respondents reported outage costs upwards of $1 million.
Besides financial losses, businesses reported facing reputational damage and compliance breaches.
Notably, in October 2021, Facebook’s network was unavailable for six hours. This network failure resulted in an estimated revenue loss of $99.75 million before users could get back online. That’s a loss of over $16 million per hour.
Now, most businesses won’t lose as much revenue as Facebook. But hourly downtime costs continue to rise and should be taken seriously.
The 2021 Cost of Data Breach Study by IBM and the Ponemon Institute reports that 91% of companies experience $300,000 or more in financial loss for every hour of downtime. When converted to minutes, that comes out to at least $4,998 per minute.
If there is one lesson to be learned from these events, it’s that CTOs and CIOs should be concerned about downtime. Not only does it add costs, but it can also damage the company's reputation and negatively impact customer experience.
If your business requires reliable IT services, consider server clusters. They are a critical investment for long-term growth and performance. A clustered environment will boost performance and ensure infrastructure availability, scalability, and reliability.
Melanie Purkis is the Director of Liquid Web's Managed Hosting Products & Services. Melanie has more than 25 years of experience with professional leadership, project management, process development, and technical support experience in the IT industry.
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