AWS Certified Associate SAA-C03 Syllabus Exam Questions Answers

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.

Correct Approach:

AWS Security Groups:

Security groups operate at the instance level, making them the ideal tool for controlling access to specific resources such as an Amazon RDS database.

By default, security groups deny all incoming traffic. You can allow access by explicitly specifying another security group.

Associating an RDS database security group with the EC2 instances' security group ensures only the specified EC2 instances can access the RDS database.

Incorrect Options Analysis:

Option A: Using CIDR blocks for IP-based access is less secure and more difficult to manage. Additionally, Auto Scaling groups dynamically allocate IP addresses, making this approach impractical.

Option B: Network ACLs (NACLs) operate at the subnet level and are stateless. While NACLs can deny or allow traffic, they are not suited to application-specific access control.

Option D: Similar to Option B, using a NACL with CIDR ranges for EC2 IPs is difficult to manage and not application-specific.

To handle unpredictable traffic surges and improve scalability, Auto Scaling is essential. Creating an AMI and deploying it into an Auto Scaling group behind an Application Load Balancer (ALB) allows AWS to automatically scale the number of EC2 instances based on demand.

This architecture improves availability and responsiveness by distributing traffic and launching instances when needed. Option A satisfies the need for high scalability and resilience. Other options either lack Auto Scaling or are more complex without added benefit in this context.

Serving static content from Amazon S3 is highly cost-effective and scalable. By fronting the S3 bucket with Amazon CloudFront, you also enable global caching, reduced latency, and even lower costs by reducing direct S3 access. There is no need for EC2 or ALB, and no need to manage servers, further lowering operational burden and expenses. This pattern is the recommended AWS architecture for serving static web content.

Reference Extract from AWS Documentation / Study Guide:

"Hosting static websites on Amazon S3 with Amazon CloudFront reduces infrastructure costs and improves performance for global users by caching content at edge locations."

Source: AWS Certified Solutions Architect – Official Study Guide, S3 and CloudFront section.