Exam AWS Certified Solutions Architect - Professional topic 1 question 33 discussion

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.

For a read-only news reporting site that needs to handle unpredictable traffic demands, the architecture should be designed for high availability and scalability. Let's evaluate the options: A. Stateless instances for the web and application tier synchronized using ElastiCache Memcached in an autoscaling group monitored with CloudWatch and RDS with read replicas. Stateless instances are ideal for scalability since they don't maintain any session information. If one instance fails, users can be directed to another instance without any disruption. ElastiCache Memcached can be used to cache frequent database queries or session data, reducing the load on the database. Autoscaling ensures that the application can scale out or in based on demand. CloudWatch monitors the performance and can trigger scaling actions. RDS with read replicas can handle a large number of read requests by distributing the load across multiple replicas.

Why we would need ElastiCache to sync web/app tier up if they are stateless?

"read-only" -> read replicas "unpredictable traffic " -> autoscaling -> stateless

A. read only. read replica.

high availability is not the requirement

A. RDS with read replicas offer better performance so handle unexpected traffic not multi-AZ RDS which only focuses on high availability.

A for me. Chose A because it also has memcache as well as read replicas. Both will defo speed up throughput and allow it to meet unexpected traffic demands.

My answer is A. The only difference between A and D is “RDS with read replicas” and “multi-AZ RDS”. Question only focus on high traffic, no HA requirement for multi-AZ.

why not B?what's the difference between A and B?

D. already cache there to handle reads, which will forward to only primary RDS. Multi AZ makes more sense

A Correct

go with A

Multi AZ is just backup, doesn't help improve throughput. So A

A. Stateless + AutoScaling + CloudWatch + Read-Replicas

my answer is D.