DVA-C02 Troubleshooting and Optimization Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Create a CloudFront invalidation for the updated objects.

  Why this is correct

  Creating a CloudFront invalidation is the precise and recommended method to force edge locations to remove specific cached objects. When an object in the origin is updated, an invalidation request explicitly tells CloudFront to delete the old version from all edge caches, compelling subsequent user requests for that object to fetch the newest version directly from the origin. This ensures immediate content freshness across the entire distribution without affecting other cached items.

• ✗

  Disable and re-enable the CloudFront distribution.

  Why it's wrong here

  Disabling a CloudFront distribution causes a complete service interruption, making all content served through it temporarily unavailable to end-users. While re-enabling it would eventually restore service, this drastic action is not an efficient or appropriate mechanism for merely updating specific cached content. It introduces unnecessary downtime and does not guarantee immediate cache refresh for individual objects, making it a highly disruptive and inefficient solution.

• ✗

  Update the object key in the S3 bucket.

  Why it's wrong here

  Updating an object's key, such as its filename, in the S3 bucket effectively creates a new, distinct object with a new URL. CloudFront's edge caches, however, would continue to serve the *original* object under its *old* key until its configured TTL expires or an explicit invalidation is performed for that old key. This approach necessitates updating all references to the object across your application, which is cumbersome and fails to address the problem of stale content being served from the original URL.

• ✗

  Change the default TTL to 0.

  Why it's wrong here

  Changing the default TTL (Time To Live) setting in a CloudFront distribution only dictates the caching duration for *newly ingested* objects. This modification does not retroactively affect or invalidate objects already present in CloudFront's edge caches; those existing objects will continue to be served based on their original TTL. Therefore, simply adjusting the TTL will not immediately propagate updated content to users, as it fails to address the stale content already residing at the edge.

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