Amazon Web Services SAA-C03 Online Access

Elastic Fabric Adapter (EFA) is a network interface for Amazon EC2 instances that enables high throughput, low-latency networking, and OS-bypass capabilities. EFAs are designed for applications that require fast inter-node communications, such as HPC, ML, and real-time analytics. EFA provides significantly lower latency than traditional networking, which is ideal for real-time streaming and processing workloads.

Reference Extract from AWS Documentation / Study Guide:

"Elastic Fabric Adapter (EFA) provides low-latency, high-throughput network communications required by high-performance computing applications, enabling fast, scalable, and tightly-coupled workloads on AWS."

Source: AWS Certified Solutions Architect – Official Study Guide, EC2 Networking section.

Export Requirements:

To export data from DynamoDB to Amazon S3, point-in-time recovery (PITR) must be enabled for the tables. This feature creates a snapshot of the data, which is essential for exports.

Incorrect Options Analysis:

Option B: S3 buckets and DynamoDB tables do not need to be in the same region for exports.

Option C: DynamoDB streams are unrelated to the export functionality.

Option D: DAX accelerates reads but has no role in exports.

EBS Encryption:

Default EBS Encryption: Can be enabled for new EBS volumes.

Use of AWS KMS: Specify AWS KMS keys to handle encryption and decryption of data transparently.

Amazon RDS Encryption:

RDS Encryption: Encrypts the underlying storage for RDS instances using AWS KMS.

Configuration: Enable encryption when creating the RDS instance or modify an existing instance to enable encryption.

Least Amount of Changes:

Both EBS and RDS support seamless encryption with AWS KMS, requiring minimal changes to the existing infrastructure.

Enables compliance with regulatory requirements without modifying the application.

Operational Efficiency: Using AWS KMS for both EBS and RDS ensures a consistent, managed approach to encryption, simplifying key management and enhancing security.

Private subnets require outbound internet access to download updates, but they must not have public IPs or direct inbound access.

The recommended AWS solution is to create a NAT gateway in a public subnet. Private subnet route tables are updated to route internet-bound traffic (0.0.0.0/0) to the NAT gateway. The NAT gateway then uses the internet gateway attached to the VPC to communicate with the internet.

Option B (NAT instances) is an older approach and less scalable/maintainable than NAT gateways. Option C (egress-only internet gateway) is for IPv6 outbound-only traffic, not IPv4. Option D is invalid because NAT gateways must be deployed in public subnets.