A retailer runs a primary application stack behind an Application Load Balancer in ap-southeast-2 and an identical warm standby stack behind another Application Load Balancer in us-west-2, reachable through the public domain shop.example.com. The team wants Amazon Route 53 to send all users to the primary while it is healthy and to redirect new requests to the standby automatically, within minutes, only when the primary stack stops responding, using the existing domain name and the least custom code. Which two configuration choices implement this active-passive Regional failover? Select TWO.
- AUse Route 53 latency-based routing between the two Application Load Balancers so users are always sent to the Region with the lowest latency for their location.
- BCreate two Route 53 failover records for shop.example.com, marking the ap-southeast-2 Application Load Balancer as Primary and the us-west-2 one as Secondary so traffic shifts only on primary failure. Correct
- CUse Route 53 weighted routing with the primary at weight 100 and the standby at weight 0, then have an operator raise the standby weight by hand during an outage.
- DAttach a Route 53 health check to the primary record that monitors a health endpoint on the ap-southeast-2 stack, so Route 53 stops returning the primary when it becomes unhealthy. Correct
- EEnable cross-zone load balancing on the primary Application Load Balancer so that user requests keep being served even if the entire ap-southeast-2 Region fails.
Why A is wrong: Latency routing splits live traffic across both Regions by network latency, which is active-active load distribution, not the active-passive failover the requirement specifies.
Why B is correct: Failover routing with a Primary and a Secondary record sends all traffic to the primary while healthy and switches to the standby on failure, which is exactly the active-passive behaviour required.
Why C is wrong: Weighted records do not react to health on their own, so a manual weight change defeats the automatic within-minutes failover requirement and adds operational toil.
Why D is correct: A health check on the primary record is what lets Route 53 detect the outage and stop answering with the primary, triggering the automatic failover to the standby within minutes.
Why E is wrong: Cross-zone load balancing only spreads traffic across Availability Zones within one Region; it does nothing for a Regional failure and cannot move traffic to us-west-2.