Horizontal vs Vertical Scaling: A 101 Guide to Cloud Scaling & Growth (2024)

In the modern business world, businesses need an IT capability that’s fast, flexible, and reliable. To achieve this, many are moving to cloud-based technology, with providers such as Microsoft Azure dominating the $153.6 billion cloud hosting market.

But when organizations need to enhance their cloud capabilities, it’s hard to know which scaling strategy is the best to take. The two most popular scaling strategies, horizontal and vertical, and the common routes – but how do you know which one is right for you?

What is Cloud Scaling & Cloud Scalability?

In cloud computing, scalability describes your technology’s ability to increase and decrease in size and capability to meet day-to-day changes in demand. With many people now utilizing external providers such as Azure and AWS for their cloud computing needs, this scalability is something organizations need their suppliers to provide.

To help understand the concept, let’s bring scalability to life. Imagine you’re running a web portal that manages a demand of 1000 users per day. Your infrastructure has the bandwidth, processing power, and resilience to comfortably manage that demand. Let’s say you launch a new product and drive an additional 1000 users to the portal; that’s a 100% increase in demand – could your systems handle that?

Systems that are scalable can, with servers, nodes, and databases that are able to react almost instantly to an increased workload without lengthy upgrades or periods of downtime. This helps you stay online and react to your customer’s needs.

Scalability is something all modern businesses want, but there are many different ways to achieve it. Let’s look at the two most common models, horizontal and vertical scaling.

What is Horizontal Scaling?

Horizontal scaling involves the addition of new servers and nodes to increase capacity across multiple machines. Rather than simply relying on the capacity of a single machine, scaling horizontally sees companies adding more machines to deal with an increase in demand.

For example, imagine you were running a server with 1 CPU, 32GB RAM, and 10TB storage. To horizontally scale, you would add servers with the same specifications to complement the first. So, if you had 3 of these servers, your overall capability would grow to 3 CPU’s, 96GB RAM, and 30TB storage.

This concept isn’t specific to computing resources. Business teams have been using this scaling system for years, bringing more people into the team and spreading the work as their organizations grow – it’s the same concept!

What is Vertical Scaling?

On the other hand, vertical scaling increases the existing machine’s capacity to drive better performance. Rather than implementing multiples of the same capability, when you scale vertically, you invest in that single server or node, increasing its ability to handle an increased workload by way of an upgrade.

Again, if we use the previous example of a server with 1 CPU, 32GB RAM, and 10TB storage, vertical scaling may increase the capacity by upgrading to 64GB RAM and 20TB storage to handle additional demand.

Again, this concept of adding additional capacity isn’t unique to managed cloud scaling. For years, businesses have invested in training their people to learn new skills and techniques to enable them to handle more advanced tasks – again, it’s the same concept!

The Key Differences Between Horizontal and Vertical Scaling

Now that we know what scaling horizontally and vertically looks like, let’s compare the key differences between the two. If you need to scale, horizontal scaling and vertical scaling are both good options but do work differently in reality.

Let’s explore some of the differences now.

Scaling Execution

Horizontal Scaling – You’re scaling in and out as you add more nodes/servers in a distributed computing model.

Vertical Scaling – You’re scaling up and down as you increase or decrease the computing power of a single node.

Ongoing Maintenance

Horizontal Scaling – More maintenance overhead as you have more infrastructure to upgrade, service, and modify.

Vertical Scaling – Less maintenance as you still have the same number of nodes, just with more power.

Implementation Downtime

Horizontal Scaling – None. When you scale horizontally, your existing infrastructure can stay running throughout.

Vertical Scaling – Some. When you upgrade a single server, it will need downtime to replace components and perform upgrades.

Work Distribution

Horizontal Scaling – Work is spread evenly across multiple machines, with different machines responsible for other tasks.

Vertical Scaling – Work is isolated to one machine, with techniques such as cross-threading used to allocate resources to different types of requests,

Implementation and Run Costs

Horizontal Scaling – There are high initial costs to implement more infrastructure, but over time, costs can be optimized.

Vertical Scaling – There are low initial costs to implement upgrades, but if not fully utilized, vertical scaling isn’t a good cloud cost management solution.

How to Choose the Right Scaling Solution for Your Business – Horizontal vs Vertical Scaling

You now have all the key information on vertical scaling and horizontal scaling to begin to choose the right solution for your business.

To finish this article, let’s look at the pros and cons of each to help you make the best decision for your organization.

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Pros of Horizontal Scaling

The advantages of horizontal scaling are:

• Easier to Execute – Using horizontal scaling is a more straightforward strategy as you’re essentially copying and pasting your existing config to another machine.
• Better Resilience – Having multiple machines gives you security if one was to fail. This reduces single point of failure risk and helps you react faster when disaster strikes.
• Less Downtime – While horizontal scaling may require you to add extra machines, this scaling strategy means you won’t have to turn off any existing machines.

Cons of Horizontal Scaling

The disadvantages of horizontal scaling are:

• Higher Upfront Costs – By adding additional machines, horizontal scaling would cost your business more upfront versus vertical scaling approaches.
• More To Maintain – Horizontal upgrades require more work and effort from the team as the same patches, fixes, and version upgrades need to be completed multiple times.
• More Supplier Coordination – Depending on your cloud service provider, this type of scaling may require more management with suppliers as you have more assets to oversee.

Pros of Vertical Scaling

The advantages of vertical scaling are:

• Cost Effective – Because vertical scaling focuses on upgrading existing machines, it’s likely to cost you less upfront.
• Less Management Overhead – Vertical scaling also means less management overhead as you still have just one overall asset to manage. This is great when working with suppliers such as Azure and AWS Cloud as there’s less complexity in your contract.
• Simpler Maintenance – Vertical scaling allows you to keep your maintenance simple as you’ll only have one machine to maintain – this means patches, fixes, and upgrades only need to be applied once.

Cons of Vertical Scaling

The disadvantages of vertical scaling are:

• More Downtime – If you’re scaling often, a vertical option will inevitably lead to more downtime as you’re upgrading in-place resources.
• Failure Risk – The key standout when you compare vertical and horizontal scaling is the failure risk. By continually vertically scaling, you put all of your resources into one machine, which, if it fails, could bring your operation to a halt.
• Capability Limitation – If you continually use this type of scaling strategy, eventually, you will reach the limit of what one machine, server, or node can deliver. This may not be a problem in the short term, but over time, it may lead to some challenges.

The Key Things to Consider

Based on the advantages and disadvantages of horizontal and vertical scaling, we’d recommend taking the following routes:

• If you’re looking for a short-term scaling solution that’s cost-effective and easy to implement, vertical scaling could be the best strategy for your business growth ambitions.
• If you’re looking for a long-term scaling solution that maximizes performance, reduces risk, and requires less downtime, a horizontal strategy would be what’s right for your business.
  

It’s Time to Boost your Business Through a Mix of Horizontal Scaling and Vertical Scaling Strategies

In a time when businesses everywhere need to maximize their IT performance, having flexible and scalable cloud-based platforms is essential for success. Horizontal and vertical scaling strategies are the most common, helping organizations move quickly while managing cost, risks, and downtime.

Even when you’re armed with the right cloud scaling knowledge, organizations achieve the best results when they partner with the right experts. At Inetum, we have years of experience helping clients achieve their cloud transformation goals by leveraging the power of Microsoft Azure, whether through a full-scale cloud implementation or tactical capability enhancement.

If you’d like to take the next steps, find out more about what we offer by visiting the Cloud Services page on our website or reach out to us!