AWS Certified Developer – Associate (DVA-C02) — Question 399

A company uses AWS X-Ray to monitor a serverless application. The components of the application have different request rates. The user interactions and transactions are important to trace, but they are low in volume. The background processes such as application health checks, polling, and connection maintenance generate high volumes of read-only requests.

Currently, the default X-Ray sampling rules are universal for all requests. Only the first request per second and some additional requests are recorded. This setup is not helping the company review the requests based on service or request type.

A developer must configure rules to trace requests based on service or request properties. The developer must trace the user interactions and transactions without wasting effort recording minor background tasks.

Which solution will meet these requirements?

Answer options

• A. Disable sampling for high-volume read-only requests. Sample at a lower rate for all requests that handle user interactions or transactions.
• B. Disable sampling and trace all requests for requests that handle user interactions or transactions. Sample high-volume read-only requests at a higher rate.
• C. Disable sampling and trace all requests for requests that handle user interactions or transactions. Sample high-volume read-only requests at a lower rate.
• D. Disable sampling for high-volume read-only requests. Sample at a higher rate for all requests that handle user interactions or transactions.

Correct answer: C

Explanation

To ensure that all critical, low-volume user interactions and transactions are recorded, sampling must be disabled for these requests so that 100% of them are traced. Conversely, high-volume, read-only background requests should be sampled at a lower rate to prevent them from overwhelming the system and incurring unnecessary costs. The other options either fail to guarantee the capture of all critical transactions or sample the high-volume background noise too aggressively.