AWS Certified Solutions Architect – Professional — Question 679

A company runs an application in the cloud that consists of a database and a website. Users can post data to the website, have the data processed, and have the data sent back to them in an email. Data is stored in a MySQL database running on an Amazon EC2 instance. The database is running in a VPC with two private subnets. The website is running on Apache Tomcat in a single EC2 instance in a different VPC with one public subnet. There is a single VPC peering connection between the database and website VPC.
The website has suffered several outages during the last month due to high traffic.
Which actions should a solutions architect take to increase the reliability of the application? (Choose three.)

Answer options

• A. Place the Tomcat server in an Auto Scaling group with multiple EC2 instances behind an Application Load Balancer.
• B. Provision an additional VPC peering connection.
• C. Migrate the MySQL database to Amazon Aurora with one Aurora Replica.
• D. Provision two NAT gateways in the database VPC.
• E. Move the Tomcat server to the database VPC.
• F. Create an additional public subnet in a different Availability Zone in the website VPC.

Correct answer: A, C, F

Explanation

To achieve high availability and handle traffic spikes, the Tomcat web tier needs to scale horizontally using an Auto Scaling group and an Application Load Balancer (A), which requires a second public subnet in a different Availability Zone (F) to avoid a single point of failure. Migrating the self-managed MySQL database on EC2 to Amazon Aurora with an Aurora Replica (C) introduces managed scaling, high availability, and automatic failover for the data tier. Other options, such as adding redundant VPC peering connections (B) or moving the Tomcat server to the database VPC (E), do not resolve the primary scaling and single-instance bottlenecks.