SAP-C02 Question 466
Select 3A financial services company has a strict SLA with its customers, requiring 99.99% availability for its web application. The application is hosted on AWS using EC2 instances behind an Application Load Balancer (ALB), with data stored in an RDS database. During a recent audit, you discover that the application is only achieving 99.9% availability. Which of the following architectural changes would help meet the SLA requirements while maintaining cost efficiency?
- A
Enable Multi-AZ deployment for the RDS database.
- B
Configure Auto Scaling for the EC2 instances with health checks.
- C
Use AWS Global Accelerator to route traffic to the application across multiple AWS Regions.
- D
Move the application to a single, more powerful EC2 instance to reduce potential failure points.
- E
Implement Route 53 health checks with DNS failover to a backup Region.
Show answer and explanation
Correct answers: A, B, E
Explanation
To meet the SLA of 99.99% availability, the architecture needs to reduce failure points and ensure automatic recovery from failures. Multi-AZ RDS ensures database availability, Auto Scaling maintains EC2 instance resilience, and Route 53 health checks with DNS failover provide redundancy across Regions. While AWS Global Accelerator and a single powerful EC2 instance may help in certain scenarios, they are either less cost-efficient or do not align with the SLA's high availability requirements.
- A. Correct.
Enabling Multi-AZ deployment for RDS improves availability by ensuring that a secondary database instance is ready to take over in case of failure, which supports achieving the required SLA.
- B. Correct.
Configuring Auto Scaling with health checks ensures that failed EC2 instances are replaced automatically, improving fault tolerance and availability.
- C. Incorrect.
While AWS Global Accelerator improves performance and fault tolerance across multiple Regions, it may not be cost-effective unless the SLA explicitly requires a multi-Region setup.
- D. Incorrect.
Moving to a single, more powerful EC2 instance increases the risk of a single point of failure, which decreases availability and goes against the SLA requirements.
- E. Correct.
Route 53 health checks with DNS failover provide a backup mechanism to switch to a different Region in the event of a failure, supporting higher availability.