Story of Kubernetes (k8s)

Monolithic Systems

• Lets assume we are builing an ecommerce system
  
• Ecommerce has different modules
  • user registration and management
  • administration
  • catalog
  • warehousing
  • logistics
  • cart
  • payment
  • notifications
• Scaling: During the seasonal sale, we have more than normal users accesing our application, we need to scale servers
  
• Application Updates:
  • We need to increase number of servers if we need zero downtime
  • Rollout the new version on servers (atleast one server should be up)
  • In the cases of problems with latest version (Rolling back) but the above steps are challenging and require expertise

Microservices

• Applications are broken down into individually runnable services
• Read the comic book Refer Here
• Google has a history of running containers and to operate on this containers they have built orchestration systems
  • OMEGA
  • BORG
• Docker was released and Was a popular option to run containers
• Google has written the orchestration system based on their experince with containers in GOlang which is called as Kubernetes and made it opensource.
• Kubernetes, also known as K8s, is an open source system for automating deployment, scaling, and management of containerized applications.
• Running containers for Production Scenarios is what k8s does.
• Alternatives to k8s
  • Docker Swarm
  • Apache Mesos
  • AWS ECS
• Kubernetes creates a cluster which is combination of multiple nodes categorized as
  • Worker node (node):
    • Here the application workloads are executed
  • Master Node:
    • They manage the cluster