The distributed, strongly-consistent key-value store behind Kubernetes — consensus, watches, and keeping critical state safe.

Welcome to etcd: The Consistent Brain of Distributed Systems.

etcd is the distributed, strongly-consistent key-value store that distributed systems trust with their most critical data — and the database behind Kubernetes. This free book teaches it from first principles: the consensus problem and the Raft algorithm that gives etcd its consistency, its architecture and MVCC data model, the API of keys, watches, leases, and transactions and the coordination primitives built on them, how etcd powers Kubernetes and why its health is the cluster's health, clustering and quorum, performance tuning (where disk latency rules), backup and disaster recovery, security, and operating etcd in production. Ten focused chapters with real commands and clear diagrams that demystify the reliable source of truth at the heart of Kubernetes and many other systems — and show how to run and protect it.

This title is part of the ShriIra library and is free to read in full, right here — our small contribution to making world-class knowledge easy to reach.

A note on reading it: open the Contents menu at the top of the reader to jump between chapters, use the Aa menu to set a comfortable text size, theme (light, sepia, or night), and single- or two-page layout. Your place is saved automatically, so you can always pick up where you left off.

We hope it serves you well.

— Shriira Press

Contents

1. Chapter 1 — What etcd Is
2. Chapter 2 — Consensus and the Raft Algorithm
3. Chapter 3 — Architecture and Data Model
4. Chapter 4 — The API: Keys, Watches, Leases, and Transactions
5. Chapter 5 — etcd and Kubernetes
6. Chapter 6 — Clustering and Membership
7. Chapter 7 — Performance and Tuning
8. Chapter 8 — Backup and Disaster Recovery
9. Chapter 9 — Security
10. Chapter 10 — Operating etcd and Putting It Together