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terms in kubernetes


Node - node is machine physical or virtual on which kubernetes is installed. node is a worker machine on which container will installed by kubernetes. Was also known as minions in the past. Was also known as minions in the past.
What if the machine on which container is running goes down.
For this, we need to have more than one nodes

Cluster -  is a group of nodes set together. This way even if one node fails we have our application accessible from other. Also helps in balancing load.

Who manages the clusters. failure load management etc?
Ans - Master
Master is another node with kubernetes installed in it and is configured as a master. Watches over the nodes in the cluster and is responsible for actual orchestration of containers in the worker nodes.

When we install kubernetes, we are actually installing the following systems
Components
1. Api server
2. etcd service
3. kubelet service
4. container Runtime
5. controllers
6. schedulers

The API server acts as front end for kubernetes.
The users, management devices , cli , all talk to the API server to interact with Kubernetes cluster.

etcd keystore - > is a reliable key value store used by Kubernetes to store all data used to manage the cluster. Whe nyou have multiple nodes and multiple  Masters in your cluster, etcd stores all the information on all the nodes in the cluster in a distributed manner. etcd is responsible for implementing locks within the cluster to ensure that there are no conflicts between the Masters.

Scheduler - > is reponsible for distributing work or container across multiple nodes. It looks for newly created containers and assigns them to nodes.

Controllers -> brains behind orchestration. Responsible for noticing and responding when nodes, containers or endpoints goes down. The controllers make the decision to bring up new containers in such cases.

Kubelet - > is the agent that runs on each node in the cluster. It is responsible for making sure that the containers are running on the nodes as expected. So far,

There are two types of servers 1. Master and 2. Workers

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