Question #1712
A company operates a web application that uses an embedded NoSQL database hosted on Amazon EC2 instances. The application is fronted by an Application Load Balancer (ALB) and uses an EC2 Auto Scaling group deployed in a single Availability Zone. The company needs to enhance the application's availability and ensure the database achieves eventual consistency with minimal operational effort.
Which solution meets these requirements with the LEAST operational overhead?
Replace the ALB with a Network Load Balancer. Continue hosting the NoSQL database on EC2 instances with its existing replication setup.
Configure the Auto Scaling group to distribute EC2 instances across three Availability Zones. Retain the embedded NoSQL database and manage its replication manually on the EC2 instances.
Replace the ALB with a Gateway Load Balancer. Migrate the embedded NoSQL database to Amazon DynamoDB using AWS DMS.
Update the Auto Scaling group to span three Availability Zones. Migrate the embedded NoSQL database to Amazon DynamoDB using AWS Database Migration Service (AWS DMS).
Explanation
Option D is correct because:
1. Multi-AZ Auto Scaling: Distributing EC2 instances across three Availability Zones enhances application availability by eliminating single-AZ dependency.
2. Managed Database (DynamoDB): Migrating to DynamoDB removes the operational burden of managing database replication manually. DynamoDB inherently provides high availability, automatic multi-AZ replication, and eventual consistency.
Other options fail because:
- A: Replacing ALB with NLB does not address database availability or reduce operational effort.
- B: Manual database replication increases operational overhead.
- C: Gateway Load Balancer is unsuitable for standard web traffic, and DynamoDB migration is correct, but GLB replacement is unnecessary.
Key Points: Use multi-AZ deployments for availability and managed services (e.g., DynamoDB) to minimize operational effort.
Answer
The correct answer is: D