情境
A user request triggers recursive DNS resolution; authoritative DNS applies health-based routing. When the primary cloud region fails health checks, DNS returns the secondary region IP, redirecting traffic without manual intervention.
這張圖裡有什麼
看懂背後的決策。
01
Use health check monitor to continuously validate primary and secondary region availability
02
Route DNS answers to secondary region IP when primary health check fails
03
Keep TTL low enough to allow fast failover but not overload resolvers
Reuse for designing DNS failover architectures, documenting incident runbooks for regional cloud outages, or explaining health-check-driven routing to stakeholders.