How to Build a 99.99% High‑Availability Service: Practices and Architecture Evolution
This article explains the essential requirements for achieving 99.99% service availability—consistency, eliminating single points, placement groups, traffic isolation, same‑city active‑active, N+1 redundancy, and multi‑region active‑active—illustrated with a step‑by‑step Yum repository service case study and evolving architecture diagrams.
