Infrastructure

How to explain vertical and horizontal scaling in the cloud

Share this post:

cloud-scalingIn this world of cloud, one of the biggest features is the ability to scale. There are different ways to accomplish scaling, which is a transformation that enlarges or diminishes. One is vertical scaling and the other is horizontal scaling.

What is the difference between the two? If you look at just the definitions of vertical and horizontal you might see the following:

• Vertical: something that is standing directly upright at a right angle to the flat ground
• Horizontal: something that is parallel to the horizon (the area where the sky seems to meet the earth)

If you are a visual kind of person you may be able to see this. Let’s add some technology to this and see what we get.

Vertical scaling can essentially resize your server with no change to your code. It is the ability to increase the capacity of existing hardware or software by adding resources. Vertical scaling is limited by the fact that you can only get as big as the size of the server.

Horizontal scaling affords the ability to scale wider to deal with traffic. It is the ability to connect multiple hardware or software entities, such as servers, so that they work as a single logical unit. This kind of scale cannot be implemented at a moment’s notice.

So, having said all that, I always like to provide an example that you might be able to visually imagine.

Imagine, if you will, an apartment building that has many rooms and floors where people move in and out all the time. In this apartment building, 200 spaces are available but not all are taken at one time. So, in a sense, the apartment scales vertically as more people come and there are rooms to accommodate them. As long as the 200-space capacity is not exceeded, life is good.

This could even apply to a restaurant. You have seen the signs that tell you how many people could be held in the establishment. As more patrons come in more tables may be set up and more chairs added (scaling vertically). However when capacity is reached no more patrons would be able to fit. You can only be as big as the building and patio of the restaurant. This is much like in your cloud environment, where you could add more hardware to the existing machine (RAM and hard drive space) but you are limited to capacity of your actual machine.

On the horizontal scaling side, imagine a two lane expressway. The expressway is good to handle the 2,000 or so vehicles that travel the expressway. As commerce begins to expand, more buildings are constructed and more homes are built. As a result the expressway that once handled 2,000 or so vehicles is now having an increase to 8,000 vehicles. This makes a major traffic jam during rush hour. To alleviate this problem of traffic jams and an increase in accidents, the expressway can be scaled horizontally by constructing more lanes and quite possibly adding an overpass. In this example the construction will take some time. Much like scaling your cloud horizontally, you add additional machines to your environment (scaling wider). This requires planning and making sure you have resources available as well as making sure your architecture can handle the scalability.

I think this could be a simple way to explain scalability to a customer if they wanted to know the difference between vertical and horizontal scaling in the cloud. What are your thoughts? How have you described scalability? Leave a comment below and let me know.

Staff Software Engineer IBM Commerce

More Infrastructure stories

With cloud, Jenzabar brings new simplicity to higher education

Today’s students have grown up with digital technologies and naturally expect their higher education experience to involve fast and convenient tools and processes. However, many higher education technology providers are held back by inefficient, rigid on-premises systems. At Jenzabar, we built a transformational software-as-a-service (SaaS) solution in the IBM Cloud to help education clients reduce […]

Continue reading

Accelerating high performance computing in the cloud with IBM and Rescale

High performance computing (HPC) is helping enterprises across industries tackle some of the world’s most complex challenges, from helping a petroleum company handle complex fluid dynamics simulations for reservoir modeling to supporting automotive companies as they design autonomous vehicles to helping aerospace companies create the next rocket or airplane design. When the potential of HPC […]

Continue reading

SIFI removes barriers to international growth with SAP and IBM Cloud

Ophthalmology is a highly specialized area of healthcare and a challenging sector. Creating pharmaceuticals and medical devices requires significant investment, especially for organizations that want to manufacture and sell innovative products internationally. Different countries each have their own rigorous quality standards and certifications, so expanding into new markets increases complexity. SIFI’s strategy is to grow […]

Continue reading