Removing Cached Copies of Objects with Prefix 'folder-a' in Professional Cloud Network Engineer Exam

C.

The correct answer is B. Issue a cache invalidation command with pattern /folder-a/*.

Explanation:

Cloud CDN is a content delivery network service offered by Google Cloud Platform that helps to improve the performance, reliability, and scalability of web applications and websites by caching static and dynamic content closer to end-users.

In this scenario, the storage bucket has four objects, all of which have been successfully cached. The goal is to remove the cached copies of all the objects with the prefix "folder-a" using the minimum number of commands.

Option A suggests adding a lifecycle rule on the storage bucket. While this could be a valid solution, it would not necessarily be the minimum number of commands required to solve the problem.

Option B suggests issuing a cache invalidation command with a pattern of /folder-a/. This is the correct answer because it is the most efficient way to remove the cached copies of all the objects with the prefix "folder-a". Cloud CDN allows you to invalidate specific cache items or patterns, which forces Cloud CDN to fetch the latest version of the object from the origin storage bucket. Issuing a cache invalidation command with the pattern /folder-a/ will remove all the cached copies of objects with the prefix "folder-a" without affecting other cached objects.

Option C suggests making sure that all the objects with the prefix "folder-a" are not shared publicly. While this is good practice, it is not related to the problem at hand.

Option D suggests disabling Cloud CDN on the storage bucket, waiting 90 seconds, and then re-enabling Cloud CDN. While this would remove all cached copies, it is not the minimum number of commands required to solve the problem.

In summary, the most efficient way to remove cached copies of all the objects with the prefix "folder-a" is to issue a cache invalidation command with the pattern /folder-a/*.