Amazon Web Services Updated SAA-C03 Exam Questions and Answers by elspeth

Understanding the Requirement: The robotics company needs a public load balancer to ensure seamless communication with backend services, route traffic based on query strings, and encrypt traffic.

Analysis of Options:

Network Load Balancer with ACM Certificate: NLBs primarily operate at the transport layer (Layer 4) and do not natively support query parameter-based routing, which is a Layer 7 feature.

Gateway Load Balancer with IAM Certificate: Gateway Load Balancers are designed for deploying, scaling, and managing third-party virtual appliances and do not support HTTP path-based or query parameter-based routing.

Application Load Balancer with ACM Certificate: ALBs operate at the application layer (Layer 7), supporting features like query parameter-based routing and SSL/TLS termination with ACM certificates.

Network Load Balancer with IAM Certificate: As with the first option, NLBs do not support query parameter-based routing, making it unsuitable for this requirement.

Best Solution:

Application Load Balancer with ACM Certificate: This option provides the necessary Layer 7 routing capabilities and SSL/TLS termination to meet the requirements for query parameter-based routing and encrypted communication.

Amazon Elastic File System (Amazon EFS) is a fully managed, elastic, shared file system that can be mounted concurrently by multiple EC2 instances across multiple Availability Zones. EFS automatically grows and shrinks as files are added or removed, providing seamless scalability for unpredictable and growing storage needs. It supports simultaneous access from multiple compute resources, making it ideal for applications where several EC2 instances must read and write to the same data set concurrently. EBS volumes cannot be shared across multiple Availability Zones, and S3 Glacier is intended for archival and infrequent access, not for active, hourly data analysis.

Reference Extract from AWS Documentation / Study Guide:

"Amazon EFS provides a scalable, fully managed elastic NFS file system for use with AWS Cloud services and on-premises resources. It can be mounted to many EC2 instances across multiple Availability Zones and is ideal for shared data scenarios."

Source: AWS Certified Solutions Architect – Official Study Guide, Storage Solutions section; Amazon EFS User Guide.

For bidirectional communication such as chat applications, Amazon API Gateway WebSocket API is the correct service. WebSocket APIs allow clients to establish long-lived connections and exchange messages with the backend Lambda functions in real time.

HTTP APIs and REST APIs are suitable for request-response models, not continuous two-way communication. CloudFront cannot maintain stateful WebSocket connections, so only Option C fits the requirements for a real-time, bidirectional application.

Amazon CloudFront is a global content delivery network (CDN) that caches and distributes content to users with low latency. By setting the existing ALB as the origin, CloudFront can cache dynamic and static content closer to users worldwide, improving performance and reducing the load on the application servers. This is the most cost-optimized and AWS-recommended way to globally serve dynamic content for web applications.

Reference Extract:

"CloudFront accelerates delivery of both static and dynamic content, reducing latency and offloading origin resources by caching content at edge locations."

Source: AWS Certified Solutions Architect – Official Study Guide, CloudFront and Global Application section.