Q24 — AWS SAA-C03 Ch.15

Question 24 of 100 | ← Chapter 15

Q1124. A company deployed an application in two AWS Regions. If the application becomes unavailable in one Region, the application must fail over to the second Region.The failover process must avoid stale DNS client caches. The company wants to use one endpoint to access both copies of the application.Which solution will meet these requirements?

• A. Use an Amazon CloudFront distribution that has multiple origins. Correlate each origin with the application in each Region.
• B. Use an Amazon Route 53 weighted routing policy that uses equal weights to route client requests to the second Region if the application becomes unavailable in the original Region.
• C. Use AWS Global Accelerator, and assign a static anycast IP address to the application endpoint. ✓
• D. Use an Amazon Route 53 IP-based routing policy to route requests to the second Region if the application becomes unavailable in the original Region.

Correct Answer: C. Use AWS Global Accelerator, and assign a static anycast IP address to the application endpoint.

Explanation

The best solution to meet the requirements for a failover process that avoids stale DNS client caches and uses one endpoint to access both copies of the application is:C. Use AWS Global Accelerator, and assign a static anycast IP address to the application endpoint.Explanation:AWS Global Accelerator provides a static IP address that routes traffic to the optimal region based on health checks and routing policies. This allows for seamless failover between regions without the need for DNS updates, effectively avoiding issues with stale DNS client caches.- The static IP address remains the same regardless of which region the application is serving from, providing a consistent access point for users.Why Other Options Are Not Suitable:A: While using Amazon CloudFront can help with content delivery, it does not inherently provide the same level of failover capability between regions as AWS Global Accelerator.B: Using a Route 53 weighted routing policy does not effectively handle the issue of stale DNS caches because DNS changes can take time to propagate, leading to potential downtime during failover.D: An IP-based routing policy in Route 53 also suffers from the same issue of DNS caching, which can delay failover and leave clients pointing to an unavailable region.Therefore, option C is the most appropriate solution for achieving reliable failover with minimal latency and stale DNS issues.