AWS Certified Solutions Architect – Professional — Question 705

An online retail company hosts its stateful web-based application and MySQL database in an on-premises data center on a single server. The company wants to increase its customer base by conducting more marketing campaigns and promotions. In preparation, the company wants to migrate its application and database to AWS to increase the reliability of its architecture.
Which solution should provide the HIGHEST level of reliability?

Answer options

• A. Migrate the database to an Amazon RDS MySQL Multi-AZ DB instance. Deploy the application in an Auto Scaling group on Amazon EC2 instances behind an Application Load Balancer Store sessions in Amazon Neptune.
• B. Migrate the database to Amazon Aurora MySQL. Deploy the application in an Auto Scaling group on Amazon EC2 instances behind an Application Load Balancer. Store sessions in an Amazon ElastiCache for Redis replication group.
• C. Migrate the database to Amazon DocumentDB (with MongoDB compatibility). Deploy the application in an Auto Scaling group on Amazon EC2 instances behind a Network Load Balancer. Store sessions in Amazon Kinesis Data Firehose.
• D. Migrate the database to an Amazon RDS MariaDB Multi-AZ DB instance. Deploy the application in an Auto Scaling group on Amazon EC2 instances behind an Application Load Balancer. Store sessions in Amazon ElastiCache for Memcached.

Correct answer: B

Explanation

Amazon Aurora MySQL provides the highest database reliability and durability through its fault-tolerant, self-healing storage system that replicates data across multiple Availability Zones. For the stateful application tier, storing session state in an Amazon ElastiCache for Redis replication group ensures high availability and automatic failover, whereas Memcached lacks replication features and Neptune is a graph database not suited for session state. An Auto Scaling group behind an Application Load Balancer completes this highly reliable and scalable architecture.