etcd
What it is
etcd is an open-source, self-hosted key-value store for data used by distributed systems and clusters of machines. It organizes values in hierarchical directories and lets clients watch keys or directories for changes; values can also be read and written with HTTP tools such as curl. The project distributes data using the Raft protocol and describes the store as strongly consistent. It handles leader elections during network partitions and can tolerate machine failures, including loss of the leader. Keys can have optional time-to-live expiration. etcd is a core Kubernetes component and the primary Kubernetes datastore. It is available as pre-built binaries, source builds, and container images. Linux on AMD64 and ARM64 is tier 1; Darwin and Windows on those architectures are tier 3, while unlisted platforms are unsupported. TLS and client-certificate authentication are supported for client and peer communication, but are not enabled by default. The project typically maintains only its latest two minor versions. etcd is licensed under Apache 2.0 and costs nothing.
For and against
For
- Hierarchical key-value storage supports change watches.
- Optional time-to-live expiration for keys.
- Tolerates machine failures, including leader failure.
- Available as binaries, source builds, and container images.
Against
- TLS and client-certificate authentication are off by default.
- Darwin and Windows are tier 3 platforms.
- Unlisted platforms are unsupported.
- Typically maintains only the latest two minor versions.
The verdict
etcd offers distributed key-value storage with Kubernetes integration and optional key expiration. Check platform support and enable the available security features as needed for your deployment.
Who it suits
It suits teams that need a self-hosted datastore for distributed systems or Kubernetes. Users should account for its platform tiers and security settings, which are off by default.
Plans and prices
Open-source etcd
Apache 2.0 licensed · self-hosted software
Read 4 Oct 2026 · github.com
On the record
- Consensus
- The project says etcd is distributed using the Raft protocol.etcd.io · read 4 Oct 2026
- Expiry
- Keys can be configured with optional time-to-live expiration.etcd.io · read 4 Oct 2026
- Fault tolerance
- It handles leader elections during network partitions and can tolerate machine failure, including failure of the leader node.etcd.io · read 4 Oct 2026
- Installation
- The project provides pre-built binaries, source builds, and container images; its install guide warns that OS package manager installations may be outdated and are not officially supported.etcd.io · read 4 Oct 2026
- Integrations
- The integrations listing includes Kubernetes, CoreDNS, and client libraries for multiple languages; it cautions that third-party tools and libraries listed there are not tested or maintained by the etcd team.etcd.io · read 4 Oct 2026
- Interface
- Values can be read and written using standard HTTP tools such as curl.etcd.io · read 4 Oct 2026
- Key-value storage
- It stores data in hierarchically organized directories and lets clients watch keys or directories for changes.etcd.io · read 4 Oct 2026
- Kubernetes
- etcd is a core Kubernetes component and the primary datastore for Kubernetes.etcd.io · read 4 Oct 2026
- License
- The etcd source repository identifies the software as licensed under Apache 2.0.github.com · read 4 Oct 2026
- Performance
- The project states etcd is benchmarked at thousands of writes per second per instance.etcd.io · read 4 Oct 2026
- Purpose
- etcd is a strongly consistent, distributed key-value store for data accessed by distributed systems or clusters of machines.etcd.io · read 4 Oct 2026
- Security
- etcd supports TLS and client-certificate authentication for client-to-server and peer communication, but these security features are not enabled by default.etcd.io · read 4 Oct 2026
- Supported platforms
- The current platform table lists Linux on AMD64 and ARM64 as tier 1; Darwin and Windows on AMD64 or ARM64 are tier 3, and unlisted platforms are unsupported.etcd.io · read 4 Oct 2026
- Support policy
- The project typically maintains only its latest two minor versions; its 2025 release announcement said those were v3.5 and v3.6 at that time.etcd.io · read 4 Oct 2026
