Q46 — AWS SAA-C03 Ch.17

Question 46 of 89 | ← Chapter 17

Q1346. A global ecommerce company is designing a three-tier application on AWS. The application includes a web tier that serves static content. An application tier handles business logic. A database tier stores product information and user data. The application interacts with a relational database. The company needs a highly available application architecture to serve global users with the low latency. Which solution will meet these requirements with the LEAST operational overhead?

• A. Deploy Amazon EC2 instances in an Auto Scaling group for the application tier and web tier in a single AWS Region. Use an Application Load Balancer to distribute web traffic. Use an Amazon RDS database and Multi-AZ deployments for the database tier.
• B. Set up an Amazon CloudFront distribution that uses an Amazon S3 bucket as the origin. Use Amazon ECS containers on AWS Fargate to deploy the application tier to each AWS Region where the company operates. Use an Amazon Aurora global database for the database tier. ✓
• C. Use an Amazon S3 bucket to store the static web content. Use Amazon EC2 Auto Scaling and EC2 Spot Instances for the application tier. Use Amazon RDS for MySQL with read replicas for the database tier. Use AWS DMS to replicate data to secondary AWS Regions.
• D. Use an Amazon S3 bucket to store static web content. Use AWS Lambda functions to handle serverless backend logic in the application tier. Use Amazon API Gateway to invoke the Lambda functions for web requests. Use an Amazon DynamoDB database for the database tier. Deploy the DynamoDB data base across multiple AWS Regions.

Correct Answer: B. Set up an Amazon CloudFront distribution that uses an Amazon S3 bucket as the origin. Use Amazon ECS containers on AWS Fargate to deploy the application tier to each AWS Region where the company operates. Use an Amazon Aurora global database for the database tier.

Explanation

The correct solution is B. Set up an Amazon CloudFront distribution that uses an Amazon S3 bucket as the origin. Use Amazon ECS containers on AWS Fargate to deploy the application tier to each AWS Region where the company operates. Use an Amazon Aurora global database for the database tier.Explanation:Requirements Recap:High Availability (HA): The architecture must minimize downtime. Low Latency for Global Users: Content should be served from the nearest AWS Region. Least Operational Overhead: The solution should minimize manual management (e.g., scaling, patching, replication).Why Option B is correct:Web Tier (Static Content):Amazon CloudFront + S3: CloudFront is a global CDN that caches static content (e.g., images, CSS, JS) at edge locations worldwide, reducing latency for global users. S3 provides highly durable and scalable storage for static assets.Application Tier (Business Logic):Amazon ECS on AWS Fargate: Fargate is a serverless container service that automatically scales and manages infrastructure, reducing operational overhead compared to EC2 Auto Scaling. Deploying ECS in multiple Regions ensures high availability and low latency.Database Tier (Relational Data):Amazon Aurora Global Database: Aurora Global Database provides cross-Region replication with minimal latency (typically < 1 second). It supports automatic failover to a secondary Region, ensuring high availability while maintaining strong consistency for transactional workloads.Why the other options are incorrect:A. Single-Region Deployment with Multi-AZ RDSLimited Global Reach: Deploying all tiers in a single Region increases latency for users far from that Region.No Multi-Region HA: While Multi-AZ RDS improves database availability within a Region, it does not protect against Region-wide failures or provide low latency globally.C. EC2 Spot Instances + AWS DMS for ReplicationHigher Operational Overhead: Managing EC2 Spot Instances requires handling interruptions and potential cost fluctuations.Complex Data Replication: AWS DMS adds complexity for cross-Region replication, whereas Aurora Global Database handles this automatically.Read Replicas Lag: MySQL read replicas may introduce latency, affecting real-time consistency.D. DynamoDB Global Tables (NoSQL)Incorrect Database Type: The requirement specifies a relational database, but DynamoDB is a NoSQL database.Serverless Trade-offs: While Lambda + API Gateway reduces operational overhead for the application tier, DynamoDB's eventual consistency model may not suit transactional workloads requiring strong consistency.Conclusion:Option B provides the best balance of high availability, low latency, and minimal operational overhead by leveraging:CloudFront + S3 for global static content delivery.ECS on Fargate for serverless, scalable business logic.Aurora Global Database for managed cross-Region replication with strong consistency. This architecture ensures the application is resilient, performant, and easy to maintain.