What is Horizontal and Vertical Scaling in the Cloud?

Horizontal and Vertical Scaling

When it comes to easy scaling of tech resources, the cloud platform continues to deliver both flexibility and agility to business applications, which is why many organizations are lining up to migrate to the cloud. Without easy scalability, no organization can truly achieve digital transformation. As more organizations switch from on-premises data centers to the cloud network, cloud service providers like AWS, Microsoft Azure, and Google Cloud are providing the flexibility to add (or remove) computing power at any time. 

How do organizations achieve cloud scalability? Primarily, there are two forms of scaling on the cloud, namely, Horizontal and Vertical scaling. While horizontal scaling is all about adding more instances to existing server infrastructure, vertical scaling is about improving computing power with faster CPUs, memory upgrades, and more resources.

What are the pros and cons of each of these scaling methods, and which one is right for your organization? Let us check out. 

Pros and Cons of Horizontal Scaling

As compared to vertical scaling, horizontal scaling is easier to implement, hence is the more preferred mode of scaling deployed by most enterprises. Also referred to as “scaling out,” horizontal scaling can be effective in increasing server capacity by adding more server instances, without changing the capacity of the individual servers in the cluster. 

Horizontal scaling can be achieved using techniques like load balancing, clustering, or a distributed file system. With the use of load balancers to handle more user requests, horizontal scaling can automatically achieve scalability in the event of higher user expectations and workload. This scaling method is also more fault-tolerant as in the event of any cloud server going down, another provisional server can be requisitioned to take over the operation.

Horizontal scaling is also suitable for running a business website that can expect an increase in web traffic with the growth of the business. More traffic leads to an increased workload on the existing cloud servers and cluster nodes. With horizontal scaling, more servers (or nodes) can be added to distribute the increased load resulting from higher incoming traffic. 

Pros of horizontal scaling:

  • Cost-effective as compared to vertical scaling
  • Easier for adding more servers to the existing pool of cloud servers
  • Reduces individual server workload thus improving its performance
  • Improved fault tolerance and resilience
  • Easier to upgrade
  • Easier to implement with minimum downtime

Cons of horizontal scaling:

  • Inconsistent data generated from multiple machines
  • Requires more cross-server communication
  • Costs could increase as the number of generated instances increase
  • Possible over-utilization of machines leading to an outage
  • Probability of hardware issues for smaller machines
  • Complex server architecture


Next, let us discuss the pros and cons of vertical scaling.

Pros and Cons of Vertical Scaling

Also referred to as “scaling up,” vertical scaling is all about increasing the computing power of existing servers, instead of just increasing the number of instances of physical servers. On its part, vertical scaling involves the upgrading of machine resources by increasing their processing power, memory, or storage. For example, you can choose to upgrade a database server with a memory capacity of 10GB to 1TB to process more data requests.

With vertical scaling, there are no techniques like load balancing or partitioning done to improve the scaling. Effectively, it involves improving the processing capability of individual servers to handle the higher workload. Vertical scaling is often limited to the computing capacity of each cloud server. Vertical scaling is also referred to as “right-sizing” as it requires the right estimation of CPU and memory resources for executing a specific application instance.

Vertical scaling is suitable for small-to-medium businesses that may not have the provisioned budget to buy more expensive computers or servers. Additionally, it is suited for basic applications that work with limited users and a low number of data requests. 

Pros of vertical scaling:

  • Lower upfront costs
  • Minimum application code changes for higher server configuration
  • The convenience of running application instances on the same server
  • Easier for increasing CPU and memory capacity
  • Lower cloud implementation costs using right-sizing

Cons of vertical scaling:

  • Higher costs when computing resources are not rightly sized for applications
  • Higher possibility of unavailability or application downtime
  • Higher probability of server downtime due to failures
  • Failure to respond to multiple and simultaneous requests
  • Scaling limited to machine configuration

Horizontal or vertical scaling. Which of these are better for your business? Let’s check next.

Horizontal or Vertical Scaling – Which is right for your organization?

The main difference between horizontal and vertical scaling is how cloud computing resources are added to the existing infrastructure. Vertical scaling (or “scaling up”) involves adding more computing or processing power to the existing setup, while horizontal scaling (or “scaling out”) involves adding more capacity with more servers or instances.

Which of these scaling methods are better suited for your business enterprise? For a start, horizontal scaling is suitable for enterprises with large applications and business operations that require computing capabilities like high concurrency, workload distribution, and minimum downtime. On the other hand, vertical scaling is suitable for small-to-medium enterprises as they have smaller operations and limited budgets.

When it comes to running business applications, the choice between horizontal and vertical scaling depends on the answers to the following questions:

  • How accessible should your application be to users?
  • How important is application uptime for your business?
  • How do you plan to improve your cloud capacity for more application users?

Horizontal scaling would be preferred when organizations do not want to exhaust their computing resources for building and deploying better apps for their consumers or users. On the other hand, vertical scaling (with the right sizing) can enable organizations to optimize their cloud computing costs without compromising performance.


Scalability is just one of the many considerations when organizations decide to invest in any cloud computing solution. As discussed, both horizontal and vertical scaling have their share of advantages and limitations, hence the final decision depends on what is more suited for your business and application needs.

At Wissen, we help our clients leverage the most benefits from their investment into cloud technologies. Our team of experts works closely with companies to understand their business requirements and design the right cloud strategy services.

Do you want us to explore how to improve your cloud computing scalability? We can help you. Let’s connect.

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