Question #1261
A company operates a global web application on AWS using ten Amazon EC2 instances distributed across multiple Availability Zones. The company needs DNS queries to return the IP addresses of all healthy EC2 instances simultaneously while performing health checks on each instance.
Which routing policy should be implemented to fulfill this requirement?
Weighted routing policy
Failover routing policy
Multivalue routing policy
Geoproximity routing policy
Explanation
The Multivalue routing policy (C) is designed to return up to 8 healthy records per DNS query, with Route 53 automatically checking the health of each EC2 instance. This ensures clients receive all healthy IP addresses at once, enabling load balancing across instances.
Other options are incorrect because:
- A (Weighted): Distributes traffic based on weights but returns only one IP per query.
- B (Failover): Supports only active-passive setups, not simultaneous IP returns.
- D (Geoproximity): Routes based on geographic proximity, not health-based multi-IP returns.
Key Points:
- Multivalue routing is ideal for high availability with multiple healthy endpoints.
- Route 53 health checks are integral to this policy.
- Use Multivalue when clients need to handle load balancing across multiple IPs.
Answer
The correct answer is: C