AWS Certified Solutions Architect – Professional — Question 741

A solutions architect is deploying a web application that consists of a web tier, an application tier, and a database tier. The infrastructure must be highly available across two Availability Zones. The solution must minimize single points of failure and must be resilient.

Which combination of steps should the solutions architect take to meet these requirements? (Choose two.)

Answer options

• A. Deploy an Application Load Balancer (ALB) that is mapped to a public subnet in each Availability Zone for the web tier. Deploy Amazon EC2 instances as web servers in each of the private subnets. Configure the web server instances as the target group for the ALB. Use Amazon EC2 Auto Scaling for the web server instances.
• B. Deploy an Application Load Balancer (ALB) that is mapped to a public subnet in each Availability Zone for the web tier. Deploy Amazon EC2 instances as web servers in each of the public subnets. Configure the web server instances as the target group for the ALUse Amazon EC2 Auto Scaling for the web server instances.
• C. Deploy a new Application Load Balancer (ALB) to a private subnet in each Availability Zone for the application tier. Deploy Amazon EC2 instances as application servers in each of the private subnets. Configure the application server instances as targets for the new ALB. Configure the web server instances to forward traffic to the new ALB. Use Amazon EC2 Auto Scaling for the application server instances.
• D. Deploy a new Application Load Balancer (ALB) to a private subnet in each Availability Zone for the application tier. Deploy Amazon EC2 instances as application servers in each of the private subnets. Configure the web server instances to forward traffic to the application server instances. Use Amazon EC2 Auto Scaling for the application server instances.
• E. Deploy an Amazon RDS Multi-AZ DB instance. Configure the application to target the DB instance.
• F. Deploy an Amazon RDS Single-AZ DB instance with a read replica in another Availability Zone. Configure the application to target the primary DB instance.

Correct answer: A, E

Explanation

Option A is correct because deploying the web instances in private subnets behind a public-facing Application Load Balancer with Auto Scaling ensures high availability and security across multiple Availability Zones. Option E is correct because an Amazon RDS Multi-AZ deployment provides synchronous replication and automatic failover, eliminating the database as a single point of failure. Options B, C, D, and F are incorrect because they either compromise security by placing EC2 instances in public subnets, fail to utilize the load balancer correctly for internal routing, or do not offer automatic database failover for write operations.