Google PCA Ensure solution and operations reliability Practice Question
A company uses Cloud CDN to accelerate content delivery. They notice that some users receive stale content even after purging the cache. Which THREE factors could cause this?
⚠ Common exam trap
Google Cloud often tests the misconception that a purge is instantaneous and global, leading candidates to overlook that incomplete or failed purge requests can leave stale content at some edge locations.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The purge request did not complete successfully.
A purge request that does not complete successfully will leave cached content intact, causing users to receive stale data. Cloud CDN processes purge requests asynchronously, and if the request fails (e.g., due to network issues or invalid paths), the cache is not invalidated. This directly explains why stale content persists despite an attempted purge.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The content is compressed with gzip.
Why it's wrong here
Compression does not affect cache staleness.
- ✓
The purge request did not complete successfully.
Why this is correct
Failed purge operations leave stale cache intact.
- ✓
The content was cached at multiple edge locations and not all were purged.
Why this is correct
Purge may not propagate to all edges immediately; some edges may serve stale content.
- ✗
The CDN is configured with signed URLs.
Why it's wrong here
Signed URLs control access, not cache freshness.
- ✓
The origin server returns a long Cache-Control: max-age header, causing the CDN to ignore the purge.
Why this is correct
Purge invalidates cache, but if the origin sets a long max-age, the CDN may re-cache the old content if the origin still serves it.
Go deeper
Related to this question
Learn chapter
Introduction to Google Cloud Platform
Key term
Cloud CDN
A Cloud CDN is a network of servers spread around the world that stores copies of your website or app content so it loads faster for users no matter where they are.
Key term
Data
Data is raw, unprocessed information, like numbers, words, or measurements, that can be stored, processed, and analyzed by computers.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCA practice question is part of Courseiva's free Google Cloud certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PCA exam.