# etcd

> Apache-2.0 Raft key-value store underneath Kubernetes

**Category:** Databases  
**Pricing:** open-source  
**URL:** https://etcd.io  
**GitHub:** https://github.com/etcd-io/etcd  
**Added:** 2026-10-18

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## The Hook

etcd is a distributed key-value store for the small pieces of data a distributed system cannot afford to lose or disagree about — configuration, service discovery, locks and leader election — and it is the datastore every Kubernetes cluster keeps its state in.

## What's Good

Apache-2.0 (etcd-io/etcd), a graduated CNCF project, release v3.7.2, in development since 2013. It uses Raft to keep a replicated log consistent across nodes, exposes a gRPC API with watches, leases and transactions, and ships automatic TLS with optional client certificates. etcdctl is the command-line client, and the raft library is usable on its own in Go. ★~52.4k.

## The Catch

It is built for small, strongly consistent data, not as a message queue, cache or bulk store: values and total database size are meant to stay small, and every write goes through consensus. Production means running a cluster of three or five nodes on fast disks and handling backups, compaction and defragmentation yourself. For an app database, use Postgres; reach for etcd when you need coordination.

## Verdict

The proven store for cluster coordination and config — keep it small and run it as a proper cluster.