Containers or VMs: Which one should you consider?

Think of a time when you moved your belongings from one location to another. Maybe you chose a means that enabled faster transfer and set up of materials. If so, you might not have faced many difficulties. Think of a scenario where a developer transferred an application from one operating system to another and debugged multiple errors. Would it not be easier to bundle the application with all its related components and then port it to run in the new environment? Now, that’s something that will make the transition seamless if it happens.

This is where the concept of containers or containerization comes into the picture.

Containers virtualize a physical server’s operating system and enable packaged applications with their libraries to run on it. Pods, worker nodes, and a master node are the components of a container. Containers are in pods, and worker nodes host the pods. Users' requests are connected to the system via the master node.

A logical packaging mechanism isolates applications from the environment they run in. Decoupling makes it easier for container-based applications to be deployed consistently and with ease. Whatever the target environment may be, containers allow for easy deployment.

You might wonder why to choose containerization and not virtualization? Well, both have use-cases. But, containers offer developers and IT Ops teams a lighter unit to work with and some other benefits. Let’s explore and know more.

Containerization Vs. Virtualization

Theoretically, containerization and virtualization are somewhat similar. Both aim at optimizing resources. However, the difference lies in their processes. Virtual Machines (VMs) have their operating system, kernels, libraries, and applications. All these make VMs heavier in size. Moreover, a hypervisor isolates multiple VMs and allocates resources to each VM. 

Containers need not run an operating system. They are an isolated unit of software that share the host operating system kernel and gain access to hardware through its capabilities. Their architecture enables faster deployment of applications in remote environments. Hence, they are highly portable and lighter than virtual machines. Containerization makes it easier to focus on different tasks at once. While the Ops team can concentrate only on the management and deployment of applications, developers can focus on the application logic and its related concerns. 

How Does Containerization Work?

Kubernetes and Docker are popular container technologies. Docker is a Linux-based open-source program that helps operating systems create containers. It's a tool that speeds up and simplifies containerization and is the most popular container deployment means.  

Kubernetes is an open-source platform for orchestrating containers, and it schedules, manages, and scales containerized applications. Kubernetes facilitates services such as load balancing, managing storage, and automating rollouts and rollbacks.

When containers are created, they communicate with local hosts through Docker's network interface. As the next step, an IP address is assigned to the created container, and a process is executed to run the application designated to it. Essentially, containerization is a read-only process and involves sharing the kernel between multiple containers of the same operating system.

As a result of containerization, each container contains all components necessary for the program to run: files, libraries, and variables. Virtual machines require a different operating system, but containers do not. Because they use fewer resources, they are faster and lighter; they can be deployed on multiple servers or virtual machines. Therefore, container technology is attracting researchers' attention for various reasons [1]. 

Should You Adopt Containerization?

A growing number of organizations are adopting containers to optimize application life-cycle management. So, if you are thinking of adopting containerization, the following factors should help:

Portability - Containers can run on any operating system, virtual machines, or a developer’s PC. They are flexible, can be easily moved to on-premise devices, the cloud, and work consistently.

Easy to Maintain – As containers use microservice architecture, applications are broken into manageable components to be deployed independently. Maintenance updates don’t affect other parts of an application. Therefore, managing containers is easier.

Resource Allocation and Efficiency – Containers are ideal for automation, continuous integration, and deployment. Unlike VMs, containers weigh less and operate on minimal hardware.  A container image can be easily deployed and replicated when created. Therefore, it is easier for a server to accommodate and run more containers and decrease cloud or data center operating costs. Secondly, when an application fails within a container, another container running that application can run without any hindrance.

Enhanced Productivity – Containers save time and resources and reduce the dependency and challenges associated with VMs. They help developers build runtime environments on the same machine that doesn’t interfere with other applications running on that system. This means that developers can deploy their component consistently, regardless of where it is applied. As a result, DevOps spend less time fixing and identifying issues. Instead, they can focus on improving product features or building newer ones. 

Things to consider:

You may have the project you wish to containerize, have developers experienced in containerization and popular container tools such as Docker, Linux Containers, RedHat Openshift, and Google Kubernetes Engine. Still, containers are vulnerable as they are isolated from the host OS and containers within the same system. Moreover, containers have multiple layers. Therefore, it is crucial to secure all the layers. Primarily, containers create complex infrastructure, with one container holding a single application. It is critical to monitor containers for performance and security issues. Monitoring your containers is a more complicated task than a virtual machine. It becomes challenging to monitor more things than one would if running all applications on a single VM. Of late, container users have become aware of security concerns. They are working on improving collaboration between DevOps and Security. 

Nonetheless, containers and VMs have their use cases. Here are some ideal settings for containers and VMs:

Containers:

·   Reduce server usage

·   Numerous diverse project environments

·   Multiservice architecture application

·   Cloud-native applications creation

VMs:

·   Persistent storage

·   System security

·   Monolithic architectural applications

·   Run different and fully functional operating systems

Final word:

Containers and VMs were designed to facilitate agile software development and optimize resources. However, they have a distinct approach to accomplishing these purposes. Containerization is one of the latest trends in software development. Some organizations are following this trend to containerize their applications. Those in the industry believe that the use-case of container technology is widespread across sectors. And therefore, many will join this trend sooner, given the advantages of containerization architecture.

References:

[1] A comparative study of Containers and Virtual Machines in Big Data Environment https://bit.ly/3RkOWN1