SAA-C03 Question 285
Select 3A company is designing a high-availability architecture for its application that must serve users across multiple AWS Regions. The application requires low latency for users in each region and should remain operational even if an entire AWS Region becomes unavailable. Which combination of options satisfies these requirements?
- A
Deploy the application across multiple Availability Zones within a single AWS Region.
- B
Deploy the application in multiple AWS Regions, leveraging Route 53 for DNS-based failover.
- C
Use AWS Global Accelerator to improve latency and direct traffic to healthy endpoints in different Regions.
- D
Enable cross-region replication for application data stored in Amazon S3 to ensure data durability and availability.
- E
Host the application on a single EC2 instance with an Elastic IP for each Region.
Show answer and explanation
Correct answers: B, C, D
Explanation
To achieve high availability across multiple AWS Regions, the application must be deployed in multiple Regions, with mechanisms like Route 53 for DNS-based failover and AWS Global Accelerator for low latency and fault tolerance. Cross-region replication ensures data durability and availability. A single Region or instance solution does not meet the requirements for fault tolerance and high availability in the event of a Region failure.
- A. Incorrect.
Deploying the application across multiple Availability Zones within a single AWS Region improves high availability within that Region, but it does not protect against an entire Region failure, which is a key requirement in the scenario.
- B. Correct.
Deploying the application in multiple AWS Regions and using Route 53 enables DNS-based failover, ensuring that traffic is routed to an available Region in case of a Region failure. This meets the high availability requirement.
- C. Correct.
AWS Global Accelerator helps reduce latency by routing traffic to the nearest healthy endpoint globally. It also provides fault tolerance by directing traffic away from unhealthy endpoints, which is relevant to the scenario.
- D. Correct.
Cross-region replication in Amazon S3 ensures that data is replicated across Regions, enhancing data durability and availability even if one Region becomes unavailable.
- E. Incorrect.
Hosting the application on a single EC2 instance with an Elastic IP does not provide high availability or fault tolerance, as a single instance or Region failure would result in downtime.