Q39 — AWS SAA-C03 Ch.5

Question 39 of 65 | ← Chapter 5

Q339. A company has hired a solutions architect to design a reliable architecture for its application. The application consists of one Amazon RDS DB instance and two manually provisioned Amazon EC2instances that run web servers. The EC2 instances are located in a single Availability Zone. An employee recently deleted the DB instance, and the application was unavailable for 24 hours as a result. The company is concerned with the overall reliability of its environment. What should the solutions architect do to maximize reliability of the application's infrastructure?

• A. Delete one EC2 instance and enable termination protection on the other EC2instance. Update the DB instance to be Multi-AZ, and enable deletion protection.
• B. Update the DB instance to be Multi-AZ, and enable deletion protection. Place the EC2instances behind an Application Load Balancer, and run them in an EC2 Auto Scaling group across multiple Availability Zones. ✓
• C. Create an additional DB instance along with an Amazon API Gateway and an AWS Lambda function.Configure the application to invoke the Lambda function through API Gateway. Have the Lambda function write the data to the two DB instances.
• D. Place the EC2 instances in an EC2 Auto Scaling group that has multiple subnets located in multiple Availability Zones. Use Spot instances instead of On-Demand instances. Set up Amazon CloudWatch alarms to monitor the health of the instances. Update the DB instance to be Multi-AZ, and enable deletion protection.

Correct Answer: B. Update the DB instance to be Multi-AZ, and enable deletion protection. Place the EC2instances behind an Application Load Balancer, and run them in an EC2 Auto Scaling group across multiple Availability Zones.

Explanation

Option B is the most appropriate solution for maximizing the reliability of the application's infrastructure. Option A only provides some level of protection for the EC2 instances, but does not address the issue of the deleted DB instance.Option C introduces unnecessary complexity by adding an additional DB instance, API Gateway, and Lambda function.Option D provides some level of protection for the EC2 instances but does not address the issue of the deleted DB instance. Additionally, using Spot instances instead of On-Demand instances may introduce more unpredictability into the environment.Therefore, Option B is the best solution as it utilizes Multi-AZ deployment for the DB instance to provide automatic failover and redundancy, enables deletion protection to prevent accidental deletion of the DB instance, places the EC2 instances behind an Application Load Balancer to distribute traffic and ensure high availability, and runs the EC2 instances in an Auto Scaling group across multiple Availability Zones to automatically launch new instances in case of failures.