AWS Certified Solutions Architect – Professional — Question 426
A European online newspaper service hosts its public-facing WordPress site in a collocated data center in London. The current WordPress infrastructure consists of a load balancer, two web servers, and one MySQL database server. A solutions architect is tasked with designing a solution with the following requirements:
✑ Improve the website's performance
✑ Make the web tier scalable and stateless
✑ Improve the database server performance for read-heavy loads
✑ Reduce latency for users across Europe and the US
✑ Design the new architecture with a goal of 99.9% availability
Which solution meets these requirements while optimizing operational efficiency?
Answer options
- A. Use an Application Load Balancer (ALB) in front of an Auto Scaling group of WordPress Amazon EC2 instances in one AWS Region and three Availability Zones. Configure an Amazon ElastiCache cluster in front of a Multi-AZ Amazon Aurora MySQL DB cluster. Move the WordPress shared files to Amazon EFS. Configure Amazon CloudFront with the ALB as the origin, and select a price class that includes the US and Europe.
- B. Use an Application Load Balancer (ALB) in front of an Auto Scaling group of WordPress Amazon EC2 instances in two AWS Regions and two Availability Zones in each Region. Configure an Amazon ElastiCache cluster in front of a global Amazon Aurora MySQL database. Move the WordPress shared files to Amazon EFS. Configure Amazon CloudFront with the ALB as the origin, and select a price class that includes the US and Europe. Configure EFS cross- Region replication.
- C. Use an Application Load Balancer (ALB) in front of an Auto Scaling group of WordPress Amazon EC2 instances in one AWS Region and three Availability Zones. Configure an Amazon DocumentDB table in front of a Multi-AZ Amazon Aurora MySQL DB cluster. Move the WordPress shared files to Amazon EFS. Configure Amazon CloudFront with the ALB as the origin, and select a price class that includes all global locations.
- D. Use an Application Load Balancer (ALB) in front of an Auto Scaling group of WordPress Amazon EC2 instances in two AWS Regions and three Availability Zones in each Region. Configure an Amazon ElastiCache cluster in front of a global Amazon Aurora MySQL database. Move the WordPress shared files to Amazon FSx with cross-Region synchronization. Configure Amazon CloudFront with the ALB as the origin and a price class that includes the US and Europe.
Correct answer: A
Explanation
Option A is correct because a single AWS Region with three Availability Zones easily meets the 99.9% availability target with minimal operational overhead, while Amazon ElastiCache and CloudFront optimize read performance and latency for US/Europe users. Options B and D introduce unnecessary multi-region complexity and replication overhead, which reduces operational efficiency. Option C is incorrect because Amazon DocumentDB is a document database and cannot act as an in-memory cache for Aurora MySQL like ElastiCache does.