AWS Certified Associate SAA-C03 Passing Score

Amazon Route 53 health checks can automatically perform DNS failover to healthy endpoints. When integrated with an Application Load Balancer, this provides a highly resilient system architecture that automatically routes traffic to healthy resources across Regions or endpoints.

From AWS Documentation:

“Route 53 DNS failover automatically routes traffic away from unhealthy resources and directs it to healthy resources that you specify in DNS records.”

(Source: Amazon Route 53 Developer Guide – DNS Failover)

Why B is correct:

Route 53 health checks automatically monitor endpoint health and switch to a healthy target when the primary endpoint fails.

The failover process is automatic, with no manual updates to DNS records required.

Combined with ALB’s built-in multi-AZ resilience, this provides maximum availability.

Why others are incorrect:

A & C: Require manual DNS updates, which are not automatic and introduce latency.

D: Creating new ALBs during failover increases downtime and is operationally inefficient.

Amazon SQS provides durable, decoupled message storage for distributed systems. Using SQS as a job queue enables each EC2 instance to process a message independently. Scaling the Auto Scaling group based on the SQS queue length ensures parallelism and elasticity, aligning compute resources with workload volume.

The current architecture tightly couples image upload, resizing, and storage into a single synchronous workflow handled by EC2 instances. This increases upload latency and degrades user experience. The optimal solution is to decouple upload from processing and offload work to managed services.

Option C allows users’ browsers to upload images directly to Amazon S3 using presigned URLs, bypassing the EC2 web servers entirely. This significantly reduces server load, network hops, and request latency while improving scalability and performance. Presigned URLs also maintain security by granting time-limited, scoped access to S3.

Option D complements this by using S3 Event Notifications to invoke an AWS Lambda function whenever a new image is uploaded. The Lambda function performs the image resizing asynchronously and stores the processed image back in S3. This event-driven, serverless pattern eliminates tight coupling between upload and processing and ensures automatic scaling with minimal operational overhead.

Option A is unsuitable because Glacier is for archival storage and not designed for active uploads or processing. Option B still routes uploads through EC2, maintaining the bottleneck. Option E introduces unnecessary delays and inefficiency by resizing images on a schedule instead of reacting to upload events.

Therefore, C and D together provide the most performant, scalable, and operationally efficient image upload and processing architecture using AWS-native, event-driven services.

DynamoDB Global Tablesprovide a fully managed, multi-region, and multi-master database solution that allows you to deploy DynamoDB tables in multiple AWS Regions. This ensures high availability and resiliency across different geographical locations, providing a seamlessgaming experience for users. Usingprovisioned capacity modewithauto-scalingensures cost-efficiency by scaling up or down based on actual demand.

Option A: While on-demand capacity mode is flexible, provisioned capacity with auto-scaling is more cost-effective for predictable workloads.

Option B (DAX): DAX improves read performance, but it doesn ' t provide the multi-region replication needed for high availability and resiliency.

Option C: DynamoDB Streams with manual cross-region replication adds more complexity and operational overhead compared to Global Tables.

AWS References:

DynamoDB Global Tables