etcd

etcd

Stores the critical data of a distributed system as keys and values, with Raft consensus, a gRPC API and automatic TLS. For engineers who build or run clusters such as Kubernetes.

Made by etcd-io on GitHub. These notes are Mindket's, written from its README; the project's own files and license are in its repository.

About

What it is: etcd is a distributed key-value store for the most important data of a distributed system. Go is its language, and Raft is the consensus algorithm behind its replicated log.

Who it suits: etcd suits engineers who build or run distributed systems and need a store that every node can agree on, such as platform teams and backend developers.

Industry | Who uses it | How they use it | Example
Cloud platforms | Platform engineers | Keep shared cluster state in a replicated store | Storing configuration that every node in a cluster must agree on
Container orchestration | Kubernetes operators | Run it as the store beside Kubernetes | Keeping a cluster's core data in etcd
Software development | Backend developers | Read and write keys through the gRPC API | Reading a shared setting from several services
Distributed systems | Infrastructure teams | Rely on Raft for agreement between nodes | Deciding which node holds a role at a given time

Anyone who only needs a local settings file or a cache for one app can skip it.

Where to use it: etcd serves distributed systems and is often teamed with other software.

• Clusters of machines that share critical data
• Kubernetes, which the project names as a frequent partner
• Other tools the notes name: locksmith, vulcand and Doorman
• Your own applications, through the gRPC API

Use case | Who | What they get back
Shared configuration | Platform teams | One store that all nodes read from
Cluster coordination | Infrastructure engineers | Agreement across nodes through Raft consensus
Application data | Developers | Keys and values through a well-defined API

How to set it up: The README warns that the main branch may be unstable or broken while development goes on. Choose a release for stable use.

1. Open the project's releases page and pick a stable version.
2. Copy the code with git from the GitHub page if you want the main branch instead.
3. Follow the setup in the project's README.

How to use it: Your programs talk to etcd through its gRPC API. The project describes four aims:

• Simple: the user-facing API is gRPC and well defined
• Secure: TLS is automatic, and client certificate authentication is optional
• Fast: benchmarked at 10,000 writes a second
• Reliable: Raft keeps it properly distributed

Example: A platform team stores its cluster's critical state in etcd. The nodes agree on each change through Raft, and clients reach it over gRPC with TLS.

For newcomers and experts: etcd is a small database for the settings and facts that a group of computers must agree on. It stores each piece of data as a key with a value. A first small thing to try is storing one setting and reading it back through the API.

The design puts a well-defined gRPC API in front of a Raft replicated log. Its topics tie it to the CNCF, Kubernetes and distributed databases, and it is written in Go.

A client calls the gRPC API over TLS
The members agree on the change through Raft
The change enters the replicated log
The key and its value are stored

Good to know: This kit holds notes and a pointer to the code, so nothing runs by itself.

• License: Apache-2.0
• Cost to run: none named
• Data it reaches: whatever keys and values your systems store in it
• Not for: running the main branch where stability matters, since it may be unstable or even broken during development

On GitHub, 7 November 2026

• Stars: 52,618 (128 that day)
• Forks: 10,590
• Watching: 1,281
• Open issues and pull requests: 425
• Language: Go
• License: Apache-2.0
• Topics: cncf, consensus, database, distributed-database, distributed-systems, etcd, go, key-value, kubernetes, raft
• Trending: #13 repository of the day on GitHub trending (7 November 2026)

Links

• Code: https://github.com/etcd-io/etcd
• Website: https://etcd.io/
• Releases: https://github.com/etcd-io/etcd/releases
• Issues: https://github.com/etcd-io/etcd/issues
• Star history: https://www.star-history.com/#etcd-io/etcd&Date

Get the code

git clone https://github.com/etcd-io/etcd.git

Then follow the setup in its README. Nothing in this kit runs by itself.