kubernetes cluster architecture

Kubernetes cluster architecture : introduction

Kubernetes cluster architecture is a complex subject. Here we will try to clarify the concepts and make it easy to understand for beginners.

A node is a machine (virtual machine or a real machine)

If you have an application running in a single node and the node goes down, the application goes offline and this incurs a loss of money.

This is why we deploy our app in a cluster which is a set of nodes : if a node fails, the other nodes will execute the app and there will not be a service interrupt.

In kubernetes, there are master nodes and a set of worker nodes. A master node manages the worker nodes (it is responsible for the distribution of the traffic between the worker nodes, replaces a worker node which goes down, orchestrates the containers running inside the nodes, etc).

A masternode is a node that has kubernetes installed in it and it is configured as a masternode.

kubernetes cluster diagram

Roles of kubernetes components :

kubernetes components diagram

The Kubectl command line interface communicates with the api server.

etcd : is a key value store used to store the data needed to manage the cluster.

Scheduler: is responsible for distributing the containers across multiple nodes.

The controller: is responsible for adding containers and removing them.

Container runtime is the runtime necessary to run containers (docker)

Kubelet : is the agent running on each node in the cluster. It is responsible for monitoring the containers and checking if they are running as expected.

Masternode vs worker node

kubernetes master node worker node

This diagram shows the components explained above and their distribution on nodes.

This differs depending on whether the node is a master node or a worker node.

This kubernetes architecture tutorial for beginners arrives at its end.

If you want to deep dive into kubernetes, you can check our kubernetes pod tutorial or our kubernetes replicaset tutorial.

To check our other tutorials, you can like our how to program facebook page.

Post a Comment

Previous Post Next Post