test-a-multiregion-web-failover

# test-a-multiregion-web-failover ## When to use - Use before launch, after architecture change, during resilience exercises, or to validate recovery objectives. - Do not inject failure without approved blast radius, stop authority, customer protection, and restoration criteria. ## Procedure 1. Define user journeys, regions, failure modes, RTO, RPO, correctness invariants, exclusions, observers, and abort thresholds. 2. Map DNS, load balancing, edge, compute, sessions, identity, databases, caches, queues, object storage, secrets, and third parties. 3. Establish baseline health, replication position, backups, authority, synthetic users, telemetry, communications, and recovery ownership. 4. Inject bounded loss of a region and observe detection, routing, stale traffic, session behavior, reads, writes, jobs, and external effects. 5. Verify no split authority, duplicate action, lost acknowledgement, security regression, privacy breach, or inaccessible degraded path. 6. Restore deliberately, reconcile data and effects, drain stale work, validate caches, and prevent old-region resurrection. 7. Compare results to objectives, record gaps and owners, update runbooks, and schedule an evidence-backed retest. ## Failure plan - Abort at the agreed threshold, return authority to the last verified topology, protect users, and reconcile every accepted operation. ## Worked example A commerce site fails from one region while preserving order idempotency, payment state, account sessions, queue ownership, and accessible status. ## Done - A multiregion failover test plan records scope, topology, baseline, injection, authority, observations, recovery, and reconciliation - Routing, state, session, security, dependency, RTO, RPO, business-outcome, restoration, and retest evidence verifies resilience