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…

Placing the Tomcat server in an Auto Scaling group with multiple EC2 instances behind a load balancer distributes traffic and automatically scales the website to handle high demand, significantly improving reliability and availability.

A single VPC peering connection is sufficient for connectivity between two VPCs; provisioning an additional connection does not inherently increase reliability or address performance bottlenecks.

Migrating the MySQL database to Amazon Aurora with an Aurora Replica enhances database reliability, scalability, and availability by leveraging Aurora's fault-tolerant, self-healing storage and providing read replicas for high availability and potential read scaling.

NAT gateways enable instances in private subnets to access the internet, but they do not directly improve application reliability or handle high traffic for a public-facing website.

Moving the Tomcat server to the database VPC might simplify networking but does not resolve the single point of failure or scalability issues of the website itself.

Creating an additional public subnet in a different Availability Zone within the website VPC allows website instances to be distributed across multiple AZs, improving fault tolerance and ensuring high availability even if one AZ experiences an outage.