What is Kubernetes?
Kubernetes is a portable, extensible, open-source platform for managing containerized workloads and services, that facilitates both declarative configuration and automation. It has a large, rapidly growing ecosystem. Kubernetes services, support, and tools are widely available.
The Rise of Kubernetes
First released in 2014, Kubernetes is an open-source container orchestration tool that can automatically scale, distribute and manage fault tolerance on containers. Originally created by Google and then donated to Cloud Native Computing Foundation, Kubernetes is widely used in production environments to handle Docker containers and other container tools in a fault-tolerant manner. As an open-source product, it is available on various platforms and systems. Google Cloud, Microsoft Azure, and Amazon AWS offer official support for Kubernetes, so configuration changes to the cluster itself are not necessary.
The popularity of Kubernetes has steadily increased, with more than four major releases in 2017. K8s also was the most discussed project in GitHub during 2017, and was the project with the second most reviews.
The Docker adoption is still growing exponentially as more and more companies have started using it in production. It is important to use an orchestration platform to scale and manage your containers.
Imagine a situation where you have been using Docker for a little while, and have deployed on a few different servers. Your application starts getting massive traffic, and you need to scale up fast; how will you go from 3 servers to 40 servers that you may require? And how will you decide which container should go where? How would you monitor all these containers and make sure they are restarted if they die? This is where Kubernetes comes in.
Why you need Kubernetes and what it can do?
Containers are a good way to bundle and run your applications. In a production environment, you need to manage the containers that run the applications and ensure that there is no downtime. For example, if a container goes down, another container needs to start. Wouldn’t it be easier if this behavior was handled by a system?
That’s how Kubernetes comes to the rescue! Kubernetes provides you with a framework to run distributed systems resiliently. It takes care of scaling and failover for your application, provides deployment patterns, and more. For example, Kubernetes can easily manage a canary deployment for your system.
- Service discovery and load balancing : Kubernetes can expose a container using the DNS name or using their own IP address. If traffic to a container is high, Kubernetes is able to load balance and distribute the network traffic so that the deployment is stable.
- Storage orchestration : Kubernetes allows you to automatically mount a storage system of your choice, such as local storages, public cloud providers, and more.
- Automated rollouts and rollbacks You can describe the desired state for your deployed containers using Kubernetes, and it can change the actual state to the desired state at a controlled rate. For example, you can automate Kubernetes to create new containers for your deployment, remove existing containers and adopt all their resources to the new container.
- Automatic bin packing : You provide Kubernetes with a cluster of nodes that it can use to run containerized tasks. You tell Kubernetes how much CPU and memory (RAM) each container needs. Kubernetes can fit containers onto your nodes to make the best use of your resources.
- Self-healing : Kubernetes restarts containers that fail, replaces containers, kills containers that don’t respond to your user-defined health check, and doesn’t advertise them to clients until they are ready to serve.
- Secret and configuration management : Kubernetes lets you store and manage sensitive information, such as passwords, OAuth tokens, and SSH keys. You can deploy and update secrets and application configuration without rebuilding your container images, and without exposing secrets in your stack configuration.
Some Use-Cases of Kubernetes
1. Tinder’s Move to Kubernetes
Due to high traffic volume, Tinder’s engineering team faced challenges of scale and stability. What did they do?
The answer is, of course, Kubernetes.
Tinder’s engineering team solved interesting challenges to migrate 200 services and run a Kubernetes cluster at scale totaling 1,000 nodes, 15,000 pods, and 48,000 running containers.
Was that easy? No way. However, they had to do it for the smooth business operations going further. One of their engineering leaders said, “As we onboarded more and more services to Kubernetes, we found ourselves running a DNS service that was answering 250,000 requests per second.” Tinder’s entire engineering organization now has knowledge and experience on how to containerize and deploy their applications on Kubernetes.
2. Reddit’s Kubernetes Story
Reddit is one of the busiest sites in the world. Kubernetes forms the core of Reddit’s internal infrastructure.
From many years, the Reddit infrastructure team followed traditional ways of provisioning and configuring. However, this didn’t go far until they saw some huge drawbacks and failures happening while doing the things the old way. They moved to Kubernetes.
3. The New York Times’s Journey to Kubernetes
Today the majority of the NYT’s customer-facing applications are running on Kubernetes. What an amazing story. The biggest impact has been an increase in the speed of deployment and productivity. Legacy deployments that took up to 45 minutes are now pushed in just a few. It’s also given developers more freedom and fewer bottlenecks. The New York Times has gone from a ticket-based system for requesting resources and weekly deploy schedules to allowing developers to push updates independently.
4. Pinterest’s Kubernetes Story
With over 250 million monthly active users and serving over 10 billion recommendations every single day, the engineers at Pinterest knew these numbers are going to grow day by day, and they began to realize the pain of scalability and performance issues.
Their initial strategy was to move their workload from EC2 instances to Docker containers; they first moved their services to Docker to free up engineering time spent on Puppet and to have an immutable infrastructure.
The next strategy was to move to Kubernetes. Now they can take ideas from ideation to production in a matter of minutes, whereas earlier they used to take hours or even days. They have cut down so much overhead cost by utilizing Kubernetes and have removed a lot of manual work without making engineers worry about the underlying infrastructure.
5. Pokemon Go’s Kubernetes Story
How was Pokemon Go able to scale so efficiently became so successful? The answer is Kubernetes. Pokemon Go was developed and published by Niantic Inc., and grew to 500+ million downloads and 20+ million daily active users.
Pokemon Go engineers never thought their user base would increase exponentially to surpass expectations within a short time. They were not ready for it, and the servers couldn’t handle this much traffic.
Pokemon Go also faced a severe challenge when it came to vertical and horizontal scaling because of the real-time activity by millions of users worldwide. Niantic was not prepared for this.
The solution was in the magic of containers. The application logic for the game ran on Google Container Engine (GKE) powered by the open source Kubernetes project. Niantic chose GKE for its ability to orchestrate their container cluster at planetary-scale, freeing its team to focus on deploying live changes for their players. In this way, Niantic used Google Cloud to turn Pokémon GO into a service for millions of players, continuously adapting and improving. This gave them more time to concentrate on building the game’s application logic and new features rather than worrying about the scaling part.
Kubernetes is not a traditional, all-inclusive PaaS (Platform as a Service) system. Since Kubernetes operates at the container level rather than at the hardware level, it provides some generally applicable features common to PaaS offerings, such as deployment, scaling, load balancing, and lets users integrate their logging, monitoring, and alerting solutions. However, Kubernetes is not monolithic, and these default solutions are optional and pluggable. Kubernetes provides the building blocks for building developer platforms, but preserves user choice and flexibility where it is important.
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