etcd
| etcd | |
|---|---|
  | |
| Release | January 28, 2015[1] |
| Stable release | |
| Written in | Go |
| Service name | etcd |
| Type | Key–value database |
| License | Apache License 2.0 |
| Website | etcd |
| Repository | |
etcd is a key-value database commonly deployed with distributed systems.[3] The software is used by Kubernetes.[4] It is written in the Go programming language and published under the Apache License 2.0.
History
[edit]etcd was originally developed as part of the CoreOS project, it was first announced in June of 2013.[5] It was later donated to the Cloud Native Computing Foundation (CNCF).[6] It became a CNCF incubating project in December 2018, and graduated in November of 2020.[4][7] At the time, the maintainer team consisted of 10 members, including: Amazon, Google Cloud, IBM, Alibaba, and Red Hat.[7] As of 2018[update], all 32 of the CFNFs Kubernetes compliant distributions and platforms used etcd as their datastore.[5]
According to a 2024 report by the CNCF, the project had over 3300 contributors and at least 450 contributing companies.[8]
The first stable version of etcd, v2.0.0, was released on January 28, 2015.[1][5] v3.0.0 was released on June 30, 2016.[9]
Name
[edit]The name "etcd" is derived from the Unix convention of storing system configuration files in the /etc directory, which applies to a single system, etcd stores configurations for a distributed system, hence the appended "d" standing for "distributed".[10][11]
Architecture
[edit]The software consists of three executables:[6]
etcdetcdctletcdutl
On particular database entries, locks can be set to prevent writing by other entities while it is being used.[6] It uses the raft consensus algorithm.[7][4]
Etcd was initially inspired by Chubby, a distributed lock manager developed Google in 2006, as well as Apache ZooKeeper.[12][13][14][15]
Features
[edit]It supports TLS/SSL encryption, exposes a client-facing gRPC API,[7] and supports multiversion concurrency control,[16] and runtime cluster membership reconfiguration.[16][17]
The official IANA assigned ports for etcd are TCP 2379/2380.[1][18]
Users
[edit]Etcd is used to store cluster data by default for most Kubernetes implementations,[5][4] like AWS EKS.[19] One notable exception being Google Kubernetes Engine, whose control-plane datastore was migrated from etcd to a Spanner-based store in 2024, while preserving etcd compatibility.[20]
Kubernetes also depends on the etcd API to communicate with its datastore, meaning that all storage backends used by it are required to support the etcd API.[20][21]
See also
[edit]References
[edit]- 1 2 3 "etcd 2.0 Release - First Major Stable Release". CoreOS. 28 Jan 2015. Archived from the original on 4 Mar 2016. Retrieved 2 December 2025.
- ↑ "Release 3.7.1". 23 July 2026. Retrieved 24 July 2026.
- ↑ Dobies, Jason; Wood, Joshua. Kubernetes Operators. O'Reilly Media.
- 1 2 3 4 "etcd gets ready to graduate | AWS Open Source Blog". AWS Blog. 17 November 2020. Retrieved 2 December 2025.
- 1 2 3 4 Lee, Gyuho; Betz, Joe (11 December 2018). "etcd: Current status and future roadmap". Kubernetes. Retrieved 2 December 2025.
- 1 2 3 Burns, Brendan (2024). Designing distributed systems: patterns and paradigms for scalable, reliable services, using Kubernetes (Second ed.). Sebastopol: O'Reilly. ISBN 978-1-0981-5635-0.
- 1 2 3 4 "Cloud Native Computing Foundation Announces etcd Graduation". CNCF. 24 November 2020. Retrieved 2 December 2025.
- ↑ "etcd Project Journey Report". CNCF. 25 September 2024. Retrieved 3 December 2025.
- ↑ "Release v3.0.0 · etcd-io/etcd". GitHub. Jun 30, 2016. Retrieved 3 December 2025.
- ↑ "What Is etcd?". IBM. 1 October 2021. Retrieved 3 December 2025.
- ↑ "etcd versus other key-value stores". etcd. Retrieved 3 December 2025.
- ↑ "Google Research Publication: Chubby Distributed Lock Service". research.google.com. Retrieved 2 December 2025.
- ↑ "etcd: the Not-so-Secret Sauce in Google's Kubernetes and Pivotal's Cloud Foundry". datacenterknowledge. 16 Jul 2014. Retrieved 2 December 2025.
- ↑ "Distributed Key-Value Store etcd Graduates at CNCF". InfoQ. 29 Nov 2020. Retrieved 2 December 2025.
- ↑ "Kubernetes Podcast from Google: Episode 95 - etcd, with Xiang Li". kubernetespodcast.com. 17 Mar 2020. Retrieved 2 December 2025.
- 1 2 "CNCF to host etcd". CNCF. 11 December 2018. Retrieved 3 December 2025.
- ↑ "Runtime reconfiguration". etcd. Retrieved 3 December 2025.
- ↑ "Service Name and Transport Protocol Port Number Registry". IANA. Retrieved 3 December 2025.
- ↑ "Explore etcd Defragmentation in Amazon EKS | Containers". AWS Blogs. 25 September 2023. Retrieved 3 December 2025.
- 1 2 "Google Kubernetes Engine supports 65,000-node clusters". Google Cloud Blog. 14 Nov 2024. Retrieved 3 December 2025.
- ↑ "How etcd works with and without Kubernetes". LearnKube. Retrieved 3 December 2025.