AWS Certified Solutions Architect – Associate (SAA-C03) — Question 81

A company is running a business-critical web application on Amazon EC2 instances behind an Application Load Balancer. The EC2 instances are in an Auto Scaling group. The application uses an Amazon Aurora PostgreSQL database that is deployed in a single Availability Zone. The company wants the application to be highly available with minimum downtime and minimum loss of data.
Which solution will meet these requirements with the LEAST operational effort?

Answer options

• A. Place the EC2 instances in different AWS Regions. Use Amazon Route 53 health checks to redirect traffic. Use Aurora PostgreSQL Cross-Region Replication.
• B. Configure the Auto Scaling group to use multiple Availability Zones. Configure the database as Multi-AZ. Configure an Amazon RDS Proxy instance for the database.
• C. Configure the Auto Scaling group to use one Availability Zone. Generate hourly snapshots of the database. Recover the database from the snapshots in the event of a failure.
• D. Configure the Auto Scaling group to use multiple AWS Regions. Write the data from the application to Amazon S3. Use S3 Event Notifications to launch an AWS Lambda function to write the data to the database.

Correct answer: B

Explanation

The correct answer is B because configuring the Auto Scaling group to use multiple Availability Zones and enabling Multi-AZ for the database ensures high availability and minimizes downtime. Option A involves Cross-Region Replication, which adds complexity and operational effort. Option C, while it provides a backup solution, does not offer high availability. Option D introduces unnecessary complexity with multiple regions and S3, which is not the most efficient way to achieve high availability.