A company serves the same public content to many users through Amazon CloudFront. The origin is experiencing increased fetches because CloudFront cache hit rate is dropping. Most requests include an Authorization header and a custom header that changes per user. The response content is identical regardless of these headers. What change should the solutions architect make to restore a high cache hit rate?

Lower the TTL to a few seconds so cached objects expire sooner and origin fetches decrease.

Lowering TTL increases how frequently CloudFront has to revalidate or refetch content, which typically increases origin load and decreases cache hit rate.

Disable caching for the affected paths so CloudFront always forwards all headers to the origin.

Disabling caching removes the benefit of the cache layer. That will almost certainly reduce cache hit rate to near zero and increase origin fetches.

Force all requests to use query-string based caching and include all headers in the cache policy for correctness.

Including high-cardinality, per-user changing headers in the cache key preserves the cache fragmentation problem and keeps the hit rate low. Query-string caching does not address header-driven variability unless the cache key is explicitly designed to exclude the varying elements.

What does this SAA-C03 question test?

Authentication checks who the user is.

What is the correct answer to this question?

The correct answer is: Create a custom cache policy that excludes the Authorization header and the per-user changing custom header from the cache key. — CloudFront uses cache policies to determine which request components (headers, query strings, cookies) are part of the cache key. Because the response content is identical regardless of the Authorization header and the per-user changing custom header, those headers should not be included in the cache key. The best fix is to create a custom cache policy that excludes those headers, which reduces cache fragmentation and increases cache hit rate, lowering origin fetches. Why others are wrong: Lower TTL values generally increase revalidation/refetch frequency, reducing hit rate. Disabling caching removes caching entirely. Including all headers in the cache policy keeps the same high-cardinality behavior (different headers per user), which will continue to fragment the cache. Query-string-only caching does not automatically fix header-based cache key fragmentation if headers that vary per user remain in the cache key.

What should I do if I get this SAA-C03 question wrong?

Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.