etcd

# etcd

[![Go Report Card](https://goreportcard.com/badge/github.com/etcd-io/etcd?style=flat-square)](https://goreportcard.com/report/github.com/etcd-io/etcd)
[![Coverage](https://codecov.io/gh/etcd-io/etcd/branch/main/graph/badge.svg)](https://app.codecov.io/gh/etcd-io/etcd/tree/main)
[![Tests](https://github.com/etcd-io/etcd/actions/workflows/tests.yaml/badge.svg)](https://github.com/etcd-io/etcd/actions/workflows/tests.yaml)
[![codeql-analysis](https://github.com/etcd-io/etcd/actions/workflows/codeql-analysis.yml/badge.svg)](https://github.com/etcd-io/etcd/actions/workflows/codeql-analysis.yml)
[![Docs](https://img.shields.io/badge/docs-latest-green.svg)](https://etcd.io/docs)
[![Godoc](http://img.shields.io/badge/go-documentation-blue.svg?style=flat-square)](https://godocs.io/go.etcd.io/etcd/v3)
[![Releases](https://img.shields.io/github/release/etcd-io/etcd/all.svg?style=flat-square)](https://github.com/etcd-io/etcd/releases)
[![LICENSE](https://img.shields.io/github/license/etcd-io/etcd.svg?style=flat-square)](https://github.com/etcd-io/etcd/blob/main/LICENSE)
[![OpenSSF Scorecard](https://api.securityscorecards.dev/projects/github.com/etcd-io/etcd/badge)](https://scorecard.dev/viewer/?uri=github.com/etcd-io/etcd)

**Note**: The `main` branch may be in an *unstable or even broken state* during development. For stable versions, see [releases][github-release].

<picture>
  <source media="(prefers-color-scheme: dark)" srcset="https://raw.githubusercontent.com/cncf/artwork/9870640f123303a355611065195c43ac3f27aa19/projects/etcd/horizontal/white/etcd-horizontal-white.png">
  <source media="(prefers-color-scheme: light)" srcset="logos/etcd-horizontal-color.svg">
  <img alt="etcd logo" src="logos/etcd-horizontal-color.svg" width=269 />
</picture>

etcd is a distributed reliable key-value store for the most critical data of a distributed system, with a focus on being:

* *Simple*: well-defined, user-facing API (gRPC)
* *Secure*: automatic TLS with optional client cert authentication
* *Fast*: benchmarked 10,000 writes/sec
* *Reliable*: properly distributed using Raft

etcd is written in Go and uses the [Raft][] consensus algorithm to manage a highly-available replicated log.

etcd is used [in production by many companies](./ADOPTERS.md), and the development team stands behind it in critical deployment scenarios, where etcd is frequently teamed with applications such as [Kubernetes][k8s], [locksmith][], [vulcand][], [Doorman][], and many others. Reliability is further ensured by rigorous [**robustness testing**](https://github.com/etcd-io/etcd/tree/main/tests/robustness).

See [etcdctl][etcdctl] for a simple command line client.

![etcd reliability is important](logos/etcd-xkcd-2347.png)

<sub>Original image credited to  xkcd.com/2347, alterations by Josh Berkus.</sub>

[raft]: https://raft.github.io/
[k8s]: http://kubernetes.io/
[doorman]: https://github.com/youtube/doorman
[locksmith]: https://github.com/coreos/locksmith
[vulcand]: https://github.c