KCNA Cloud Native Architecture Practice Question
In a microservices architecture, which pattern is used to prevent cascading failures by limiting the number of concurrent requests to a service?
⚠ Common exam trap
KCNA often tests the distinction between bulkhead and circuit breaker; candidates may pick circuit breaker because both address failures, but only bulkhead limits concurrency.
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
✓
Bulkhead
The bulkhead pattern isolates resources (e.g., thread pools, connection pools) for different services or operations so that a failure or overload in one area does not exhaust resources and cause cascading failures. By limiting the number of concurrent requests to a service, bulkheads contain the impact of slow or failing dependencies. This is analogous to watertight compartments in a ship.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Bulkhead
Why this is correct
Bulkhead partitioning isolates each downstream dependency into a separate resource pool with its own concurrency limit, so exhaustion of one pool cannot starve others. This directly satisfies the stem's constraint: capping concurrent requests to a service, thereby containing failures and preventing them from cascading across the microservices architecture.
- ✗
Timeout
Why it's wrong here
Timeout bounds how long a caller waits for a response, freeing threads, but it does not restrict how many concurrent requests reach the service. It is tempting because timeouts do stop callers hanging indefinitely on a slow dependency, yet the stem asks specifically for limiting concurrent request volume.
- ✗
Retry
Why it's wrong here
Retry re-sends failed requests, increasing load on an already-struggling service and worsening the cascade. It is tempting because retries with backoff genuinely handle transient network blips or brief blips in idempotent calls, but they do not cap concurrency, which is what the scenario demands.
- ✗
Circuit breaker
Why it's wrong here
A circuit breaker trips after a failure threshold, stopping calls to a failing dependency, but it reacts to errors rather than capping concurrent in-flight requests. It is tempting because it does prevent cascading failures, yet the stem's requirement is concurrency limiting, which bulkhead or rate-limiting patterns provide.
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.