How would you explain what ETCD is and what it is used for?

ETCD is a distributed key-value store with high availability and consistency, based on the Raft algorithm.

The main purpose of ETCD is to store configuration data and state information in distributed systems. It is often used in container orchestration systems (such as Kubernetes) to store metadata, configurations, and cluster information.

Key features of ETCD:

• Ensures data consistency across cluster nodes.
• Supports transactional operations.
• Allows subscribing to data changes (watch), which is useful for reactive configuration updates.

Example of use: Kubernetes stores the cluster state in ETCD so that all components have up-to-date information about deployed pods, services, and settings.