Kubernetes relies on a distributed key-value store to maintain its state and configuration data. Let’s analyze each option:

A. etcd

Correct: etcd is a distributed key-value store used as Kubernetes’ backend store. It stores all cluster data, including configurations, states, and metadata, ensuring consistency and reliability across the cluster.

B. firebase

Incorrect: Firebase is a Backend-as-a-Service (BaaS) platform for building mobile and web applications. It is unrelated to Kubernetes.

C. postgres

Incorrect: PostgreSQL is a relational database management system. While it can be used for other purposes, it is not the backend store for Kubernetes.

D. mongodb

Incorrect: MongoDB is a NoSQL database used for storing unstructured data. It is not used as Kubernetes’ backend store.

Why etcd?

High Availability: etcd is designed for distributed systems, providing strong consistency and fault tolerance.

Cluster State Management: Kubernetes uses etcd to store critical data such as pod states, service definitions, and configuration details.

JNCIA Cloud References:

The JNCIA-Cloud certification covers Kubernetes architecture, including the role of etcd. Understanding etcd’s function is essential for managing and troubleshooting Kubernetes clusters.

For example, Juniper Contrail integrates with Kubernetes to provide networking and security features, relying on etcd for cluster state management.