etcd is a distributed key-value store designed to reliably and quickly preserve and provide access to critical data. It enables reliable distributed coordination through distributed locking, leader elections, and write barriers. An etcd cluster is intended for high availability and permanent data storage and retrieval.
This is the etcd v2 documentation set. For more recent versions, please see the etcd v3 guides.
Reading and writing into the etcd keyspace is done via a simple, RESTful HTTP API, or using language-specific libraries that wrap the HTTP API with higher level primitives.
Configuration values are distributed within the cluster for your applications to read. Values can be changed programmatically and smart applications can reconfigure automatically. You'll never again have to run a configuration management tool on every machine in order to change a single config value.