Horizontal vs Vertical Scaling

To scale up or scale out? That is the question. When your business is growing and your applications need to expand accessibility, power, and performance, you have two options to meet the challenge — horizontal scaling and vertical scaling. This Touchstone blog will help you answer that question: “Should my business scale up or scale out?”

What is Scalability?

If you work in the data center industry or any other industry, you will probably hear two terms often referred to as horizontal scaling and vertical scaling, and these are the two most common buzzwords when working with data centers and data center management systems (DMS).

First, let’s explain what scalability is. Scalability is simply measured by the number of requests an application can handle successfully. Once the application can no longer handle any more simultaneous requests, it has reached its scalability limit. There are multiple scaling approaches for businesses in 2020. For example, your application may be able to successfully handle X number of requests simultaneously, but as soon as your application hits X + 1 simultaneous requests, your critical hardware resources run out and your application has reached its maximum capacity.

Which approach is right for your business?

For your business to grow, to prevent downtime, and reduce latency, you must scale your resources accordingly. You can scale these resources through a combination of adjustments to network bandwidth, CPU and physical memory requirements, and hard disk adjustments. Horizontal scaling and vertical scaling both involve adding resources to your computing infrastructure, your business stakeholders must decide which is right for your organization.

The main difference between scaling up and scaling out is that horizontal scaling simply adds more machine resources to your existing machine infrastructure. Vertical scaling adds power to your existing machine infrastructure by increasing power from CPU or RAM to existing machines.

What is vertical scaling?

Vertical scaling keeps your existing infrastructure but adds computing power. Your existing pool of code does not need to change — you simply need to run the same code on machines with better specs. By scaling up, you increase the capacity of a single machine and increase its throughput. Vertical scaling allows data to live on a single node, and scaling spreads the load through CPU and RAM resources for your machines.

Vertical scaling means adding more resources to a single node and adding additional CPU, RAM, and DISK to cope with an increasing workload. Basically, vertical scaling gives you the ability to increase your current hardware or software capacity, but it’s important to keep in mind that you can only increase it to the limits of your server. Vertical scaling also refers to increasing the number of machines in a data center by adding more resources to single nodes — but without adding additional CPUs, memory, or hard drives to allow more capacity and allow the individual node to handle an increased workload.

This can be achieved by changing the instance size, buying new, more powerful devices, or discarding old ones. Instead of buying a powerful machine, horizontal scaling means adding a simple server with a distributed computing model. If you run your application in your own data center (not in the cloud) and use Kubernetes to scale it, you get all the benefits of an on-demand server.

Drawbacks of vertical scaling

Small- and mid-sized companies most often use vertical scaling for their applications because it allows businesses to scale relatively quickly compared to using horizontal scaling. One drawback of vertical scaling is that it poses a higher risk for downtime and outages than horizontal scaling. Correctly provisioning your resources is the best way to ensure that upgrading was worth it and that your business will not experience the negative effects of vertical scaling.

What is horizontal scaling?

Horizontal scaling simply adds more instances of machines without first implementing improvements to existing specifications. By scaling out, you share the processing power and load balancing across multiple machines.

Horizontal scaling means adding more machines to the resource pool, rather than simply adding resources by scaling vertically. Vertical scaling gives you the ability to zoom in to add more servers to your network, but it also requires you to zoom out by adding a bit more power, CPU, and RAM to the existing infrastructure. Scaling horizontally is the same as scaling by adding more machines to a pool or resources — but instead of adding more power, CPUs, or RAM, you scale back to existing infrastructure. Horizontal scaling allows you to scale your data with more resources than you can add resources using vertical scaling.

How to achieve horizontal scaling?

The first step towards horizontal scaling is to remove your applications’ reliance on server-side tracking. Managed AWS Cloud and DevOps Automation solutions are a great way to ensure your organization can scale effectively and efficiently. Horizontal scaling is favored by DevOps experts because it is done dynamically automatically — scaling based on the load for optimal performance.

Factors to consider when deciding between horizontal scaling and vertical scaling

Both vertical and horizontal scaling can be performed automatically, also known as auto-scaling, as the actual process of scaling is not particularly difficult. When handling containers, both horizontal and vertical scaling automatically switches on, so you do not have to worry about manual intervention. If your cloud service provider or data center has difficulty ensuring vertical scaling, it can be easy to skip the application stage that scales horizontally and the horizontally scaling stages.

Scaling or vertical scaling is the process of moving more resources to a single server to accommodate the growth of your application. Cloud Vertical Scaling is the addition of an existing server or the replacement of a server with a more powerful server. Vertical scaling can have a few drawbacks, namely cost, and hardware failure.

What is your horizontal scaling or vertical scaling strategy?

A scaling strategy can dynamically select changes in application capacity and scale, including vertical or horizontal scaling. Scaling strategies may include the addition or removal of a single server or a number of servers in the same data center and may include a combination of vertical, horizontal, and/or hybrid scaling strategies for different data centers.

If you want superior performance, you can easily use vertical or horizontal scaling. You can also work in the same data center — scaled vertically and horizontally, if necessary — to achieve superior performance without any problems. You do not need both vertical scaling and horizontal scaling to achieve better performance; you can scale your existing machine infrastructure, pool of resources, or data center either vertically or horizontally and avoid redundancy.

Depending on the company and application, you can weigh the advantages and disadvantages of horizontal and vertical scaling and determine which is best for you.