AWS Certified Solutions Architect – Associate (SAA-C02) — Question 554

A company's ecommerce website has unpredictable traffic and uses AWS Lambda functions to directly access a private Amazon RDS for PostgreSQL DB instance. The company wants to maintain predictable database performance and ensure that the Lambda invocations do not overload the database with too many connections.
What should a solutions architect do to meet these requirements?

Answer options

• A. Point the client driver at an RDS custom endpoint. Deploy the Lambda functions inside a VPC.
• B. Point the client driver at an RDS proxy endpoint. Deploy the Lambda functions inside a VPC.
• C. Point the client driver at an RDS custom endpoint. Deploy the Lambda functions outside a VPC.
• D. Point the client driver at an RDS proxy endpoint. Deploy the Lambda functions outside a VPC.

Correct answer: B

Explanation

Amazon RDS Proxy manages a pool of database connections, which prevents a surge of AWS Lambda invocations from overwhelming the RDS instance with too many active connections. Additionally, because the RDS database is private, the Lambda functions must be configured to run inside a VPC to properly route traffic to the RDS Proxy. RDS custom endpoints do not offer connection pooling, and placing Lambda functions outside a VPC would prevent them from reaching the private database resources.