SAA-C03 Exam Preparation Material | AWS Certified Solutions Architect - Associate

Explanation:
To enable DNS resolution from AWS VPCs to on-premises DNS servers over Direct Connect or VPN, AWS recommends using Amazon Route 53 Resolver with outbound endpoints. An outbound endpoint allows DNS queries originating in the VPC to be forwarded to a customer-managed DNS server (e.g., on-prem).
Next, a forwarding rule (Forward type) must be created to forward DNS queries for the custom domain internal.example.com to the on-premises DNS IP addresses. This rule defines what domain names are forwarded and to which DNS servers.
Finally, the rule must be associated with all workload VPCs to allow those VPCs to use the rule. There is no need to deploy endpoints in every VPC ― one outbound endpoint is sufficient and can be shared across VPCs via rule association.
​Reference: Route 53 Resolver Endpoints
Best practices for hybrid DNS resolution

Explanation:
AWS Global Accelerator improves the performance and availability of applications by directing user traffic through the AWS global network of edge locations using anycast IP addresses. It reduces latency and jitter for global users accessing applications in a single Region.
Why this works:
Global Accelerator routes user requests to the nearest AWS edge location using AWS’s high-performance backbone network.
It then forwards traffic to the optimal endpoint ― in this case, the public API hosted on EC2.
This is much more cost-effective and requires less operational complexity than deploying and maintaining multiple API Gateway endpoints across regions (Option B), or setting up Direct Connect links for every international location (Option A).
Option C requires no application change and is designed specifically for latency improvement and
high availability.
​Reference: AWS Global Accelerator Documentation
Use Cases for Global Accelerator
Performance Improvements for Global Users

Explanation:
AWS advises using serverless event-driven processing to minimize operational burden and scale automatically with demand. Amazon SQS can be directly configured as an event source for AWS Lambda. With this setup, Lambda polls the queue, invokes the function, and processes messages without requiring the customer to manage infrastructure. Scaling is automatic, based on the volume of messages in the queue.
Option A (increasing instance size) still leaves scaling and management challenges.
Option B reduces cost when idle but does not address scaling.
Option D requires manual triggering and does not meet continuous processing requirements. Migrating the script to Lambda
(C) fully eliminates the need for instance management, providing scalability, reliability, and reduced operational overhead.
Reference:
• Amazon SQS Developer Guide ― Using AWS Lambda with Amazon SQS
• AWS Well-Architected Framework ― Operational Excellence Pillar

Explanation:
Amazon ElastiCache (Redis OSS) provides an in-memory cache that drastically improves read performance with minimal operational overhead.
It integrates easily with RDS and does not require schema or database changes.
EC2-based caching (Option C) increases management overhead.
DAX (Option D) accelerates DynamoDB only, not RDS.
Moving to DynamoDB (Option A) requires complete application and schema redesign.

Explanation:
A. ElastiCache: Provides in-memory caching, not suitable for persistent, scalable databases.
B. DynamoDB Streams + Lambda: Manages replication manually, increasing latency and operational complexity.
C. Aurora Global Database: Provides high availability but does not support active-active configuration.
D. DynamoDB Global Tables: Provides active-active configuration and sub-second RPO.
Reference: Amazon DynamoDB Global Tables