master branch may be in an unstable or even broken state during development. Please use releases instead of the
master branch in order to get stable binaries.
the etcd v2 documentation has moved
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, and the development team stands behind it in critical deployment scenarios, where etcd is frequently teamed with applications such as Kubernetes, fleet, locksmith, vulcand, Doorman, and many others. Reliability is further ensured by rigorous testing.
See etcdctl for a simple command line client.
etcd contributors and maintainers have bi-weekly meetings at 11:00 AM (USA Pacific) on Tuesdays. There is an iCalendar format for the meetings here. Anyone is welcome to join via Zoom or audio-only: +1 669 900 6833. An initial agenda will be posted to the shared Google docs a day before each meeting, and everyone is welcome to suggest additional topics or other agendas.
The easiest way to get etcd is to use one of the pre-built release binaries which are available for OSX, Linux, Windows, rkt, and Docker. Instructions for using these binaries are on the GitHub releases page.
For those wanting to try the very latest version, build the latest version of etcd from the
master branch. This first needs Go installed (version 1.9+ is required). All development occurs on
master, including new features and bug fixes. Bug fixes are first targeted at
master and subsequently ported to release branches, as described in the branch management guide.
First start a single-member cluster of etcd.
If etcd is installed using the pre-built release binaries, run it from the installation location as below:
The etcd command can be simply run as such if it is moved to the system path as below:
mv /tmp/etcd-download-test/etcd /usr/locale/bin/ etcd
If etcd is build from the master branch, run it as below:
This will bring up etcd listening on port 2379 for client communication and on port 2380 for server-to-server communication.
Next, let's set a single key, and then retrieve it:
ETCDCTL_API=3 etcdctl put mykey "this is awesome" ETCDCTL_API=3 etcdctl get mykey
That's it! etcd is now running and serving client requests. For more
etcd TCP ports
The official etcd ports are 2379 for client requests, and 2380 for peer communication.
Running a local etcd cluster
First install goreman, which manages Procfile-based applications.
Our Procfile script will set up a local example cluster. Start it with:
This will bring up 3 etcd members
infra3 and etcd
grpc-proxy, which runs locally and composes a cluster.
Every cluster member and proxy accepts key value reads and key value writes.
Running etcd on Kubernetes
To run an etcd cluster on Kubernetes, try etcd operator.
Now it's time to dig into the full etcd API and other guides.
- Read the full documentation.
- Explore the full gRPC API.
- Set up a multi-machine cluster.
- Learn the config format, env variables and flags.
- Find language bindings and tools.
- Use TLS to secure an etcd cluster.
- Tune etcd.
- Mailing list: etcd-dev
- IRC: #etcd on freenode.org
- Planning/Roadmap: milestones, roadmap
- Bugs: issues
See CONTRIBUTING for details on submitting patches and the contribution workflow.
See reporting bugs for details about reporting any issues.
etcd is under the Apache 2.0 license. See the LICENSE file for details.
Package main is a simple wrapper of the real etcd entrypoint package (located at github.com/coreos/etcd/etcdmain) to ensure that etcd is still "go getable"; e.g. `go get github.com/coreos/etcd` works as expected and builds a binary in $GOBIN/etcd
This package should NOT be extended or modified in any way; to modify the etcd binary, work in the `github.com/coreos/etcd/etcdmain` package.
|alarm||Package alarm manages health status alarms in etcd.|
|auth||Package auth provides client role authentication for accessing keys in etcd.|
|client||Package client provides bindings for the etcd APIs.|
|client/integration||Package integration implements tests built upon embedded etcd, focusing on the correctness of the etcd v2 client.|
|clientv3||Package clientv3 implements the official Go etcd client for v3.|
|clientv3/balancer||Package balancer implements client balancer.|
|clientv3/balancer/connectivity||Package connectivity implements client connectivity operations.|
|clientv3/balancer/picker||Package picker defines/implements client balancer picker policy.|
|clientv3/balancer/resolver/endpoint||Package endpoint resolves etcd entpoints using grpc targets of the form 'endpoint://<id>/<endpoint>'.|
|clientv3/clientv3util||Package clientv3util contains utility functions derived from clientv3.|
|clientv3/concurrency||Package concurrency implements concurrency operations on top of etcd such as distributed locks, barriers, and elections.|
|clientv3/credentials||Package credentials implements gRPC credential interface with etcd specific logic.|
|clientv3/integration||Package integration implements tests built upon embedded etcd, and focuses on correctness of etcd client.|
|clientv3/leasing||Package leasing serves linearizable reads from a local cache by acquiring exclusive write access to keys through a client-side leasing protocol.|
|clientv3/mirror||Package mirror implements etcd mirroring operations.|
|clientv3/namespace||Package namespace is a clientv3 wrapper that translates all keys to begin with a given prefix.|
|clientv3/naming||Package naming provides an etcd-backed gRPC resolver for discovering gRPC services.|
|clientv3/ordering||Package ordering is a clientv3 wrapper that caches response header revisions to detect ordering violations from stale responses.|
|clientv3/snapshot||Package snapshot implements utilities around etcd snapshot.|
|clientv3/yaml||Package yaml handles yaml-formatted clientv3 configuration data.|
|compactor||Package compactor implements automated policies for compacting etcd's mvcc storage.|
|contrib/raftexample||raftexample is a simple KV store using the raft and rafthttp libraries.|
|contrib/recipes||Package recipe contains experimental client-side distributed synchronization primitives.|
|discovery||Package discovery provides an implementation of the cluster discovery that is used by etcd.|
|embed||Package embed provides bindings for embedding an etcd server in a program.|
|error||Package error describes errors in etcd project.|
|etcdctl||etcdctl is a command line application that controls etcd.|
|etcdctl/ctlv2||Package ctlv2 contains the main entry point for the etcdctl for v2 API.|
|etcdctl/ctlv2/command||Package command is a set of libraries for etcdctl commands.|
|etcdctl/ctlv3||Package ctlv3 contains the main entry point for the etcdctl for v3 API.|
|etcdctl/ctlv3/command||Package command is a set of libraries for etcd v3 commands.|
|etcdmain||Package etcdmain contains the main entry point for the etcd binary.|
|etcdserver||Package etcdserver defines how etcd servers interact and store their states.|
|etcdserver/api||Package api manages the capabilities and features that are exposed to clients by the etcd cluster.|
|etcdserver/api/etcdhttp||Package etcdhttp implements HTTP transportation layer for etcdserver.|
|etcdserver/api/v2http||Package v2http provides etcd client and server implementations.|
|etcdserver/api/v2http/httptypes||Package httptypes defines how etcd's HTTP API entities are serialized to and deserialized from JSON.|
|etcdserver/api/v2v3||Package v2v3 provides a ServerV2 implementation backed by clientv3.Client.|
|etcdserver/api/v3client||Package v3client provides clientv3 interfaces from an etcdserver.|
|etcdserver/api/v3election||Package v3election provides a v3 election service from an etcdserver.|
|etcdserver/api/v3election/v3electionpb/gw||Package v3electionpb is a reverse proxy.|
|etcdserver/api/v3lock||Package v3lock provides a v3 locking service from an etcdserver.|
|etcdserver/api/v3lock/v3lockpb/gw||Package v3lockpb is a reverse proxy.|
|etcdserver/api/v3rpc||Package v3rpc implements etcd v3 RPC system based on gRPC.|
|etcdserver/api/v3rpc/rpctypes||Package rpctypes has types and values shared by the etcd server and client for v3 RPC interaction.|
|etcdserver/auth||Package auth implements etcd authentication.|
|etcdserver/etcdserverpb/gw||Package etcdserverpb is a reverse proxy.|
|etcdserver/membership||Package membership describes individual etcd members and clusters of members.|
|etcdserver/stats||Package stats defines a standard interface for etcd cluster statistics.|
|functional/agent||Package agent implements functional-tester agent server.|
|functional/cmd/etcd-agent||etcd-agent is a program that runs functional-tester agent.|
|functional/cmd/etcd-proxy||etcd-proxy is a proxy layer that simulates various network conditions.|
|functional/cmd/etcd-runner||etcd-runner is a program for testing etcd clientv3 features against a fault injected cluster.|
|functional/cmd/etcd-tester||etcd-tester is a program that runs functional-tester client.|
|functional/rpcpb||Package rpcpb is a generated protocol buffer package.|
|functional/runner||Package runner implements individual etcd-runner commands for the etcd-runner utility.|
|functional/tester||Package tester implements functional-tester tester server.|
|integration||Package integration implements tests built upon embedded etcd, and focus on etcd correctness.|
|lease||Package lease provides an interface and implementation for time-limited leases over arbitrary resources.|
|lease/leasehttp||Package leasehttp serves lease renewals made through HTTP requests.|
|mvcc||Package mvcc defines etcd's stable MVCC storage.|
|mvcc/backend||Package backend defines a standard interface for etcd's backend MVCC storage.|
|pkg/adt||Package adt implements useful abstract data types.|
|pkg/contention||Package contention provides facilities for detecting system contention.|
|pkg/cors||Package cors handles cross-origin HTTP requests (CORS).|
|pkg/cpuutil||Package cpuutil provides facilities for detecting cpu-specific features.|
|pkg/crc||Package crc provides utility function for cyclic redundancy check algorithms.|
|pkg/debugutil||Package debugutil includes utility functions for debugging.|
|pkg/expect||Package expect implements a small expect-style interface|
|pkg/fileutil||Package fileutil implements utility functions related to files and paths.|
|pkg/flags||Package flags implements command-line flag parsing.|
|pkg/httputil||Package httputil provides HTTP utility functions.|
|pkg/idutil||Package idutil implements utility functions for generating unique, randomized ids.|
|pkg/ioutil||Package ioutil implements I/O utility functions.|
|pkg/logutil||Package logutil includes utilities to facilitate logging.|
|pkg/mock/mockserver||Package mockserver provides mock implementations for etcdserver's server interface.|
|pkg/mock/mockstorage||Package mockstorage provides mock implementations for etcdserver's storage interface.|
|pkg/mock/mockstore||Package mockstore provides mock structures for the etcd store package.|
|pkg/mock/mockwait||Package mockwait provides mock implementations for pkg/wait.|
|pkg/netutil||Package netutil implements network-related utility functions.|
|pkg/osutil||Package osutil implements operating system-related utility functions.|
|pkg/pathutil||Package pathutil implements utility functions for handling slash-separated paths.|
|pkg/pbutil||Package pbutil defines interfaces for handling Protocol Buffer objects.|
|pkg/proxy||Package proxy implements proxy servers for network fault testing.|
|pkg/report||Package report generates human-readable benchmark reports.|
|pkg/runtime||Package runtime implements utility functions for runtime systems.|
|pkg/schedule||Package schedule provides mechanisms and policies for scheduling units of work.|
|pkg/srv||Package srv looks up DNS SRV records.|
|pkg/stringutil||Package stringutil exports string utility functions.|
|pkg/systemd||Package systemd provides utility functions for systemd.|
|pkg/testutil||Package testutil provides test utility functions.|
|pkg/tlsutil||Package tlsutil provides utility functions for handling TLS.|
|pkg/transport||Package transport implements various HTTP transport utilities based on Go net package.|
|pkg/types||Package types declares various data types and implements type-checking functions.|
|pkg/wait||Package wait provides utility functions for polling, listening using Go channel.|
|proxy/grpcproxy||Package grpcproxy is an OSI level 7 proxy for etcd v3 API requests.|
|proxy/grpcproxy/adapter||Package adapter provides gRPC adapters between client and server gRPC interfaces without needing to go through a gRPC connection.|
|proxy/grpcproxy/cache||Package cache exports functionality for efficiently caching and mapping `RangeRequest`s to corresponding `RangeResponse`s.|
|proxy/httpproxy||Package httpproxy implements etcd httpproxy.|
|proxy/tcpproxy||Package tcpproxy is an OSI level 4 proxy for routing etcd clients to etcd servers.|
|raft||Package raft sends and receives messages in the Protocol Buffer format defined in the raftpb package.|
|raft/rafttest||Package rafttest provides functional tests for etcd's raft implementation.|
|rafthttp||Package rafthttp implements HTTP transportation layer for etcd/raft pkg.|
|snap||Package snap stores raft nodes' states with snapshots.|
|snapshot||Package snapshot implements utilities around etcd snapshot.|
|store||Package store defines etcd's in-memory key/value store.|
|version||Package version implements etcd version parsing and contains latest version information.|
|wal||Package wal provides an implementation of a write ahead log that is used by etcd.|