Review Set 5 – lambda functions with Neptune DB Cluster and DynamoDB

[AudreyST]

CSAP – Design Solutions for Organizational Complexity

Q “A company is developing a serverless application that is deployed on AWS Lambda. The application consists of several Lambda functions that resize, watermark, and process images. The metadata generated from the functions is written in an Amazon DynamoDB table. The company deployed an Amazon Neptune DB cluster in three private subnets inside a VPC. A new feature was developed that requires the Lambda functions to access the Neptune DB cluster.

Which of the following options are possible solutions to allow the Lambda functions to access both the DynamoDB table and Neptune DB cluster? (Select TWO.)”

The 2 correct answer options depict an architecture with the lambda functions moved to 3 new private subnets in the same VPC as the Neptune DB, with SG of Neptune DB & lambda functions communicating, a (Gateway) VPC endpoint + a NATGW for the lambda functions to connect to the DynamoDB & internet respectively. This is all good but the diagram (see attached) shows a VPC endpoint for the Neptune DB 🤔? The lambda functions & the Neptune DB are in the same VPC, why need a VPC endpoint for the Neptune DB? Shouldn’t that be for the DynamoDB?

[Neil-TutorialsDojo]

Hello AudreyST,

Good day!

Thank you for bringing this to our attention. We apologize for any confusion caused by the diagram in the explanation.

The diagram provided was intended as a general reference to demonstrate how Lambda functions could connect to an Amazon Neptune DB cluster within the same VPC. The inclusion of the VPC endpoint in the diagram was primarily to illustrate an alternative setup. When Lambda functions are configured to run inside a VPC, they may experience a startup delay due to the ENI (Elastic Network Interface) attachment process, which can sometimes cause a delay in resolving network addresses. An alternative approach would be to run the Lambda functions outside the VPC and connect them to the Neptune DB Endpoint via a load balancer.
That said, the diagram was primarily meant to provide a broad overview rather than represent the exact architecture for the described scenario. We understand how this might have been misleading and will update the content to reflect the scenario in the question more accurately.

Your feedback is invaluable to us, as it helps ensure we maintain the highest standards in our content. We appreciate your understanding and thank you for helping us improve.

Regards,
Neil @ Tutorials Dojo