AWS Certified Associate SAA-C03 Exam Dumps

The most secure solution for allowing EC2 instances to access an S3 bucket is by usingIAM roles. An IAM role can be created with an access policy that grants the required permissions (e.g., to read and write to the S3 bucket). The IAM role is then associated with the EC2 instances through anIAM instance profile.

By associating the role with the instances, the EC2 instances can securely assume the role and receive temporary credentials via the instance metadata service. This avoids the need to store credentials (such as access keys) on the instances or within the application, enhancing security and reducing the risk of credentials being exposed.

AWS CloudFormation can be used to automate the creation of the entire infrastructure, including EC2 instances, IAM roles, and associated policies.

AWS References:

IAM Roles for EC2 Instancesoutlines the use of IAM roles for secure access to AWS services.

AWS CloudFormation User Guidedetails how to create and manage resources using CloudFormation templates.

Why the other options are incorrect:

A. Save IAM access key in UserData: This is insecure because it involves storing long-term credentials in the instance user data, which can be exposed.

B. Store access keys in S3: This is also insecure, as it involves managing and distributing long-term credentials, which should be avoided.

D. Retrieve access keys via a script: This approach is unnecessarily complex and less secure than using IAM roles, which provide temporary credentials automatically.

Explanation (AWS Docs):

You cannot “place” DynamoDB inside a VPC. Instead, you use a VPC endpoint.

A Gateway VPC Endpoint for DynamoDB enables private connectivity between your VPC and DynamoDB without traversing the public internet.

“Use a gateway VPC endpoint to privately connect your VPC to DynamoDB without requiring an internet gateway or NAT.”

— Gateway VPC Endpoints

Amazon RDS Proxy helps manage thousands of concurrent database connections by pooling and reusing them efficiently. It is especially useful for serverless applications like AWS Lambda that can open numerous connections quickly, potentially overwhelming the database. Using RDS Proxy reduces connection management overhead and improves fault tolerance.

Amazon S3 Intelligent-Tiering automatically moves objects between two access tiers based on changing access patterns. Objects not accessed for 30 days move to a lower-cost tier, but are still immediately available with millisecond retrieval. If objects become frequently accessed again, they are moved back to the frequent access tier. There are no retrieval charges and no impact on availability or performance. This storage class is specifically designed for unpredictable access patterns and cost optimization, requiring minimal management.

AWS Documentation Extract:

"S3 Intelligent-Tiering is the only storage class that automatically moves data between frequent and infrequent access tiers when access patterns change, with no retrieval charges and no impact on performance. It is designed to optimize costs automatically when data access patterns are unpredictable."

(Source: Amazon S3 documentation, Intelligent-Tiering storage class)

B: Glacier Deep Archive is for archival, not for low-latency millisecond access.

C: EFS is not optimized for object storage or global CDN distribution.

D: Cache-Control only affects CloudFront or browser caching, not S3 storage cost.