AWS Certified Solutions Architect – Professional — Question 388

A read only news reporting site with a combined web and application tier and a database tier that receives large and unpredictable traffic demands must be able to respond to these traffic fluctuations automatically.
What AWS services should be used meet these requirements?

Answer options

• A. Stateless instances for the web and application tier synchronized using ElastiCache Memcached in an autoscaimg group monitored with CloudWatch and RDS with read replicas.
• B. Stateful instances for the web and application tier in an autoscaling group monitored with CloudWatch and RDS with read replicas.
• C. Stateful instances for the web and application tier in an autoscaling group monitored with CloudWatch and multi-AZ RDS.
• D. Stateless instances for the web and application tier synchronized using ElastiCache Memcached in an autoscaling group monitored with CloudWatch and multi-AZ RDS.

Correct answer: A

Explanation

For a read-only site experiencing unpredictable traffic, utilizing stateless instances in an Auto Scaling group monitored by CloudWatch allows the application tier to scale horizontally and automatically. Because the application is read-heavy, RDS with read replicas is the optimal choice to offload read traffic from the primary database, whereas Multi-AZ deployment is primarily for high availability rather than read scaling. Stateless instances synchronized via ElastiCache Memcached ensure seamless scaling without losing session state.