KCNA Cloud Native Architecture Practice Question
A cloud-native application experiences intermittent failures when calling an external API. The team implements a pattern that allows the application to temporarily stop calling the failing API and serve stale data or a fallback response. Which resiliency pattern does this describe?
⚠ Common exam trap
KCNA often tests the distinction between resiliency patterns that stop traffic (Circuit Breaker) versus those that merely retry, isolate, or bound calls (Retry, Bulkhead, Timeout) — candidates confuse 'handling failure' with 'stopping calls and serving fallback'.
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
✓
Circuit Breaker pattern
The Circuit Breaker pattern wraps calls to a remote dependency and trips 'open' after a threshold of failures, immediately returning a fallback (stale data, cached response, or default) instead of continuing to hammer the failing API. This prevents cascading failures and gives the downstream service time to recover, while periodically probing in a 'half-open' state to test restoration. Serving stale data while the breaker is open is the classic implementation of this pattern in cloud-native apps.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Circuit Breaker pattern
Why this is correct
The circuit breaker monitors calls to the external API and, once failures cross a threshold, trips open to stop further calls, immediately returning a fallback or stale response. After a cool-down it half-opens to test recovery, matching the requirement to temporarily halt calls and serve fallback data.
- ✗
Retry pattern
Why it's wrong here
Retry re-attempts the same failing call after a delay, which keeps hammering an API already returning errors rather than serving fallback data. Retry suits transient, self-correcting faults such as a momentary packet loss or brief throttling response.
- ✗
Bulkhead pattern
Why it's wrong here
Bulkhead isolates failures by partitioning thread pools or connections per dependency, preventing one failing API from exhausting shared resources. It suits containing blast radius across multiple downstream services, not substituting stale responses when a single dependency fails.
- ✗
Timeout pattern
Why it's wrong here
Timeout bounds how long a caller waits before abandoning a request, returning an error rather than a fallback response. Timeouts suit preventing indefinite hangs on slow dependencies, not serving cached or stale data while the API recovers.
Go deeper
Related to this question
About these practice questions
One of 930 original KCNA practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CNCF exam blueprint
This KCNA practice question is part of Courseiva's free CNCF 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 KCNA exam.