Multi-Region Failover Architecture — AWS SysOps Administrator (SOA-C03)
Failover Tier Is Determined by the RTO, Not Architecture Preference
SOA-C03 multi-region questions pair a recovery objective with a scenario. "Seconds" signals active/active with Route 53 latency routing. "Minutes" signals active/passive with Route 53 failover routing and a pre-warmed standby. "Hours" signals a pilot light requiring scale-up before traffic shift. Candidates who select failover architecture based on resilience preference rather than the stated RTO will choose an answer that is architecturally valid but wrong for the specific constraint given.
What This Pattern Tests
The exam describes global availability and tests active-active vs. active-passive design. Active-active (DynamoDB Global Tables, Aurora Global Database write forwarding) serves traffic from both regions simultaneously — lower latency for global users but requires conflict resolution for concurrent writes. Active-passive (Route 53 failover, Aurora Global Database with read-only secondary) serves from one region and fails over — simpler consistency but RTO depends on failover detection and promotion time. The trap is choosing active-active without addressing write conflicts or active-passive when the scenario requires zero-downtime global access.
Decision Axis
Data consistency requirements (eventual vs. strong) and latency needs (global vs. regional) determine active-active vs. active-passive.
Associated Traps
More Top Traps on This Exam
Decision Rules
Select latency-based routing, which uses AWS-measured network latency between the requesting resolver and each regional endpoint to make a per-query routing decision, rather than weighted routing, which applies a static percentage split regardless of user location or real-time endpoint performance.
Domain Coverage
Difficulty Breakdown