AWS Certified Solutions Architect – Associate (SAA-C03) — Question 826

A company runs its application by using Amazon EC2 instances and AWS Lambda functions. The EC2 instances run in private subnets of a VPC. The Lambda functions need direct network access to the EC2 instances for the application to work.

The application will run for 1 year. The number of Lambda functions that the application uses will increase during the 1-year period. The company must minimize costs on all application resources.

Which solution will meet these requirements?

Answer options

• A. Purchase an EC2 Instance Savings Plan. Connect the Lambda functions to the private subnets that contain the EC2 instances.
• B. Purchase an EC2 Instance Savings Plan. Connect the Lambda functions to new public subnets in the same VPC where the EC2 instances run.
• C. Purchase a Compute Savings Plan. Connect the Lambda functions to the private subnets that contain the EC2 instances.
• D. Purchase a Compute Savings Plan. Keep the Lambda functions in the Lambda service VPC.

Correct answer: C

Explanation

A Compute Savings Plan is required to minimize costs because it applies discounts to both Amazon EC2 and AWS Lambda, whereas an EC2 Instance Savings Plan only covers EC2 instances. Additionally, to enable direct network connectivity to EC2 instances residing in private subnets, the Lambda functions must be configured to run inside those same private subnets within the VPC.