Q38 — AWS DVA-C02 Ch.1

Question 38 of 100 | ← Chapter 1

A developer created an AWS Lambda function written in Python. The Lambda function reads data from objects in Amazon S3 and writes the data to an Amazon DynamoDB table. The function is successfully triggered by S3 event notifications when objects are created. However, the function fails when attempting to write to the DynamoDB table. What is the most likely cause of this issue?

• A. The Lambda function’s concurrency limit has been exceeded.
• B. The DynamoDB table requires a Global Secondary Index (GSI) to support write operations.
• C. The Lambda function lacks IAM permissions to write to DynamoDB. ✓
• D. The DynamoDB table is not running in the same Availability Zone as the Lambda function.

Correct Answer: C. The Lambda function lacks IAM permissions to write to DynamoDB.

Explanation

The most likely cause is that the Lambda function lacks appropriate IAM permissions to write to DynamoDB. In AWS, inter-service interactions require explicit IAM permissions. Here, the Lambda execution role must include permissions allowing writes to the target DynamoDB table. Resolving this involves ensuring the Lambda execution role has the required DynamoDB write permissions. Other options—Lambda concurrency limits (A), need for a GSI (B), or cross-AZ deployment (D)—are unlikely root causes for write failures. 【Lantern Certification provided by: swufelp1999】