A Brief Guide to Kubernetes and Containers
A Brief Guide to Kubernetes and Containers
Compare containers and virtual machines, and see why Kubernetes has come out on top.
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Kubernetes is a platform for orchestrating containers and services, launched by Google in 2014. The key feature is that it naturally handles containers for you, monitors their availability and uses currently available computing capacity.
The Principle of Containerization
Containers are favored by developers around the world, mainly by addressing the shortcomings of classic virtualization.
With full virtualization, the hypervisor software component is installed on the physical server. This allows you to create your own resources. Each virtual machine that is created behaves like a separate server with its own operating system, which in turn causes high operating costs. It is estimated that the hypervisor for each operating system can consume up to 20% of the total server performance.
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On the other hand, containerization is a virtualization of the operating system core. Simply put, all containers run within one operating system and share a memory, libraries, and other resources.
This results in increased resource efficiency and a significant reduction in overhead costs. Besides, starting containers is much faster than starting a virtual source with operating system installation. A great advantage is also the ability to be isolated from the environment and subsequent deployment in various environments.
Scalability and High Availability
The key features of Kubernetes are automated container deployment, availability monitoring, and efficient capacity utilization. This will ensure that your app is available.
Kubernetes uses objects for different purposes. At the lowest level, we work with pods, which is the smallest deployable part of the application. For optimal load distribution, it is possible to define how many farms each service will have. These are then distributed among individual servers (nodes).There can be multiple namespaces within a cluster, allowing you to deploy multiple independent applications on a single cluster.
Kubernetes itself is free and you can run it for free. However, if you are thinking about moving to the cloud, you have to count on a fee for server hosting.
Who Can Benefit from Containers?
Containers bring many benefits. But are they suitable for you and is the transition worth it?
There is a very simple answer to this question. Anyone who works with the software can benefit from the benefits of containers. The main advantages of containerization include:
- They allow easy portability of software that can run on different devices as needed.
- Individual parts of the software can work separately, which increases overall security because the problem of one part does not affect the other.
- Containers have no competition in scaling - whether the number of users of the application decreases or increases, changes can be responded immediately.
Technically, it is possible to enclose large monolithic applications in containers, but that would not take advantage of the containers at all. Instead, it is more beneficial to divide the entire software into smaller components separately enclosed in containers.
Several methodologies describe how to break monolithic software. The more complex the links between data, the more difficult it is to break them.
What Container Solution Should You Choose?
Docker and Kubernetes are open-source products. Nothing, therefore, prevents you from operating containers on your own.
However, moving larger solutions to containers can be more difficult. If you do not have enough experience and time, you can use data center services that provide container solutions. Some providers purpose packaged Kubernetes with all the tools you'll need to use Kubernetes. For example, let's see how Jelastic did the package.
Pre-Installed Kubernetes Components Out-of-Box
- CNI plugin (powered by Weave) for overlay network support
- Traefik ingress control for routing HTTP(S) requests to services
- HELM package manager for auto-installing pre-configured solutions
- CoreDNS for internal hostnames resolution
- Dynamic provisioner of persistent volumes
- Metrics Server for gathering statistics
- Built-in SSL for protecting ingress network
- Kubernetes Web UI Dashboard
Pay-Per-Use Kubernetes Cost Efficiency
Jelastic technology provides a unique process of automatic scaling. You pay based on actual consumption, not depending on server size.
In the picture, you can see a comparison of what you lose with cloud vendors with another scaling and pricing model.
How Jelastic Pricing Works
Each hosted Jelastic PaaS container is divided into granular units — cloudlets (128MB RAM and 400 MHz CPU).
The system makes hourly measurements of the number of cloudlets consumed in each container and only requires payment for those resources.
You can set a maximum scaling limit for each container, so you can always have resources available in case of heavy load or other consumption changes.
Payments based on actual use are a huge advantage. It doesn't matter how high the limit is, the rest of the allocated resources will only wait in the reservation to be requested by the application, and it is completely free.
When choosing the right provider, it is important that you take into account not only the pricing, but also the reputation and customer support.
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