SAA-C03 Question 477
Select 2A company is running a web application on a fleet of Amazon EC2 instances behind an Application Load Balancer (ALB). The web application stores user-uploaded images in Amazon S3 and maintains metadata about the images in an Amazon RDS database. The company wants to ensure that the solution is highly available and fault-tolerant. Which of the following design choices will improve the solution's fault tolerance and availability?
- A
Enable Multi-AZ deployment for the Amazon RDS database.
- B
Configure Amazon S3 bucket versioning for the user-uploaded images.
- C
Use Auto Scaling for the Amazon EC2 instances behind the Application Load Balancer.
- D
Enable cross-region replication for the Amazon S3 bucket.
- E
Attach an Elastic IP address to the Application Load Balancer.
Show answer and explanation
Correct answers: A, C
Explanation
To improve fault tolerance and availability, enabling Multi-AZ deployment for Amazon RDS ensures automatic failover during database outages, and using Auto Scaling for the EC2 instances ensures the web tier can handle varying loads and recover from instance failures. Other options, while useful in certain contexts, do not directly address the scenario's requirements.
- A. Correct.
Enabling Multi-AZ deployment for Amazon RDS improves fault tolerance and availability by automatically failing over to a standby instance in case of an outage in the primary instance.
- B. Incorrect.
While enabling S3 bucket versioning provides data protection against accidental deletions or overwrites, it does not improve fault tolerance or availability directly.
- C. Correct.
Using Auto Scaling ensures that the EC2 instances behind the ALB can scale in or out based on demand, improving availability during traffic spikes or failures.
- D. Incorrect.
Cross-region replication for the S3 bucket helps with disaster recovery but does not directly improve availability or fault tolerance of the solution in the current region.
- E. Incorrect.
Attaching an Elastic IP address to the ALB is not supported and does not enhance fault tolerance or availability.