When it comes to scaling a system, there are two options available: Horizontal and Vertical scaling. Horizontal scaling is achieved with the help of containerization while vertical is made possible by virtualization. In this post, we shall see over both of them.

Containerization vs Virtualization

When you scale any system there are always two possible options: either you scale horizontally, or you can scale vertically. Vertical scaling comes with limitations while horizontal scaling does not have resource limitations but comes with complexity in terms of architecture and code wise.

Vertical scalability is acquired by virtualization. In virtualization, a guest operating system sits on top of the host operating system. This guest operating system shares the resources of the host operating system. The process is easy to configure. Multiple systems can run on single hardware by virtualization. But this whole process makes the overall system less portable and very bulky. Since the guest operating systems share the resources of the host operating systems, whenever scaling is required, a new resource has to be added. This new resource could either be memory or storage or even CPUs.

In horizontal scaling, we do not add resources to the system. Rather whenever a need arises to scale the application, we instead, add a new instance of the system to manage the application. This whole procedure makes the scaling easy and less costly as no new system resource has been added. Whenever we need to scale out, all we need to do is to bring down the instance. Horizontal scaling is achieved by containerization. This is a newer technology than virtualization. In containerization, a thin layer of software sits between the application and the host operating system. This thin layer of system takes care of running the container, adding or removing instances, and gracefully shutting down the application.

Hosting Apps using Kubernetes

As discussed, containerization adds new instances of the same systems. It can also run different systems on top of the container orchestration engine. To make this process easy and manageable, a platform is preferred by the developers called Kubernetes. Kubernetes is a container orchestration engine that runs Docker and other containers on top of itself. Using Kubernetes, we can not just manage the containers running but also the network and storage of these systems. Kubernetes has its own Kubernetes registry, third-party registries, and package managers such as Helm that provide software packages and version control. Kubernetes has now become a standard adoption for deployments and container orchestration.

Benefits of Containerization

When you switch over to containerization, you get many benefits straight out of the box. I am listing here a few:

1. Portability

Containerization is the tool that gives your portability from the very moment you initialize it. Based on the philosophy of write once, run anywhere; containerization ensures that your code is executed everywhere as it bundles all the dependencies in one package.

2. Faster Delivery

Having a system based on microservices, hosted on containerization, you can divide your system into small chunks or pieces. These pieces can then be developed independently and deployed hence speeding up the whole software development life cycle.

3. Secure Environment

While in virtualization, all the applications run on the same machine, containerization separates the execution environment. This means that the applications cannot interfere with each other hence isolation is ensured. With these data breaches, unauthorized access and a secure environment is acquired.

4. Management

One benefit I like most about containerization is that it is very easy to manage and configure. If for some reason you need to increase the nodes, you can create further nodes of the service as well. Now suppose if the deployment crashes you can revert to the stable version with a single click.

5. Faster Loading Time

I cannot stress this point enough. Virtualization takes a lot of time to get started because in virtualization whole host operating system needs to be initialized. On the other hand, in containerization, only apps need to be loaded hence a significant boot time is achieved for the hosted apps.

6. Agility

Applications today are not developed in iterative sprints. This is because changes in the applications are very frequent. This leads to a whole new process called Continuous Integration and Continuous Delivery. Having containerization and microservices make this process very smooth and easy.


In this post, we saw why containerization is better than virtualization. With containerization, we can save a lot of cost in terms of hardware acquisition as well as make the system manageable. Containerization is giving the best results when the system is designed based on microservices architecture. For your next system, make sure you check out containerization for hosting.