AWS Certified Developer – Associate — Question 255

A distributed application includes an AWS Lambda function that runs successfully in the DEV environment with 128 MB of memory assigned. The same function is failing in the TEST environment. The developer is monitoring the application using AWS X-Ray, but the Lambda function cannot be seen on the X-Ray service graph. The Lambda execution role has AWS X-Ray permissions.

What is the MOST LIKELY cause for AWS X-Ray not showing any data for the Lambda function?

Answer options

• A. The AWS SDK needs to be included in the AWS Lambda deployment package.
• B. VPC Flow Logs are not enabled for the application VPC.
• C. Active tracing needs to be enabled for the Lambda function.
• D. The memory needs to be increased to 2 GB for the TEST environments.

Correct answer: C

Explanation

The correct answer is C because active tracing must be enabled for AWS X-Ray to capture and display data related to the Lambda function. Options A and B are not relevant to X-Ray's ability to capture data, and option D is unnecessary as the function runs in DEV with 128 MB, indicating that memory size is not the issue.