Etcd
etcd is a CNCF graduated distributed, reliable key-value store used as the backing store for all Kubernetes cluster data. It provides strong consistency guarantees using the Raft consensus algorithm, supporting watch operations, lease-based TTLs, and atomic compare-and-swap transactions. etcd is designed for high availability and stores critical configuration data for distributed systems.
APIs
etcd gRPC API
The etcd v3 API is a gRPC-based interface providing key-value operations (put, get, delete, range), watch streams for change notifications, lease management for TTL-based keys, ...
etcd HTTP Gateway API
etcd provides an HTTP/JSON gateway that translates HTTP requests into gRPC calls, allowing clients without gRPC support to interact with etcd. The gateway supports the same oper...
etcd Concurrency API
The etcd concurrency API provides distributed primitives built on top of the core key-value store, including distributed mutexes (locks), leader election, and software transacti...
etcd Metrics API
etcd exposes a Prometheus-compatible metrics endpoint that provides operational insights into the etcd cluster, including request rates, latency histograms, disk I/O statistics,...
etcd v2 HTTP API
The original etcd v2 API exposed a RESTful HTTP interface for key-value operations using a hierarchical directory structure. This API has been deprecated in favor of the v3 gRPC...