SAA-C03 Design Resilient Architectures Practice Question

An organization hosts the same public API in two AWS Regions. Normal traffic should go to the primary Region. If the primary endpoint becomes unhealthy, Route 53 should automatically route users to the secondary Region. What is the best Route 53 configuration approach?

⚠ Common exam trap

Many candidates confuse weighted routing with failover routing, mistakenly thinking that setting a weight of 0 on the secondary is a valid way to keep it inactive until needed, but Route 53 does not automatically adjust weights based on health checks.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

Use Route 53 failover routing with health checks that mark the primary as unhealthy and fail over to the secondary.

Route 53 failover routing is designed for active-passive configurations where traffic is directed to a primary resource unless a health check marks it as unhealthy, at which point all traffic automatically shifts to the secondary resource. This directly matches the requirement of routing normal traffic to the primary Region and failing over to the secondary Region only when the primary endpoint becomes unhealthy.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
Use simple routing with one record that contains both regions as weighted targets.
Why it's wrong here
Simple routing in Route 53 does not support weighted targets and returns a single set of resource records to every DNS query without any health-check evaluation. Because it cannot associate multiple regions with weights or health checks, it cannot detect a primary Region failure and automatically reroute to a secondary. Therefore, using simple routing would not satisfy the active/passive failover requirement in this scenario.
✗
Use weighted routing and set the secondary Region weight to 0 until needed.
Why it's wrong here
Weighted routing allows you to assign traffic proportions to multiple records, but setting the secondary Region's weight to 0 only changes the distribution when you manually update the DNS configuration. Route 53 does not automatically adjust weights in response to a health check failure, so if the primary Region becomes unhealthy, clients will still receive the primary endpoint and experience failures. This approach requires manual intervention, which contradicts the need for automatic failover.
✓
Use Route 53 failover routing with health checks that mark the primary as unhealthy and fail over to the secondary.
Why this is correct
Failover routing is designed for active/passive disaster recovery. You configure a primary record and a secondary record, each associated with health checks. When the primary fails its health checks, Route 53 automatically resolves the name to the secondary target.
✗
Use latency-based routing so requests go to the region with the lowest latency, regardless of health.
Why it's wrong here
Latency-based routing selects the record that offers the lowest observed latency based on the client's location, and it does not consider the endpoint's health status when making that decision. If the nearest Region is having an outage, Route 53 will continue to direct traffic to that unhealthy target because latency remains the sole routing factor. Even when health checks are attached, the default behavior does not proactively fail over to a secondary Region for disaster recovery.

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SAA-C03 Design Resilient Architectures Practice Question

Why each option matters

Option-by-option breakdown

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