KCNA Cloud Native Application Delivery Practice Question
A Kubernetes cluster runs a critical application that must be updated with zero downtime. The team wants to gradually shift traffic from the old version to the new version over a period of time. Which deployment pattern is MOST appropriate?
⚠ Common exam trap
KCNA often tests the distinction between rolling update and canary deployment — candidates may confuse the two, but canary specifically involves gradual traffic shifting with monitoring, while rolling update is about replacing instances in batches.
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
✓
Canary deployment
Canary deployment is the most appropriate pattern for gradually shifting traffic from an old version to a new version over time. It involves deploying the new version to a small subset of users or servers, then incrementally increasing traffic while monitoring for issues. This allows zero-downtime updates and minimizes risk by limiting exposure. Rolling update replaces instances in batches but does not provide the same gradual, controlled traffic shifting with the ability to pause or rollback based on metrics.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Rolling update
Why it's wrong here
A rolling update replaces pods incrementally within a Deployment, but it cannot pause mid-rollout to shift a controlled traffic percentage between two independently running versions. It is tempting because it achieves zero downtime, yet it would be correct when you simply need all replicas updated to one new image without canary-style traffic splitting.
- ✗
Recreate deployment
Why it's wrong here
Recreate stops all old pods before starting new ones, causing downtime, which violates the zero-downtime requirement. Rolling updates replace pods incrementally while keeping the service available. Recreate suits non-critical workloads where brief unavailability is acceptable.
- ✗
Blue-green deployment
Why it's wrong here
Blue-green runs two full environments and switches all traffic at once, so it does not gradually shift traffic over time. Canary releases incrementally route a percentage of traffic to the new version. Blue-green suits instant cutover with quick rollback.
- ✓
Canary deployment
Why this is correct
Canary deployment routes a small, controlled slice of live traffic to the new version while the old version serves the remainder, then progressively shifts weight as health metrics confirm stability. This satisfies the gradual traffic-shift and zero-downtime constraints without exposing all users to risk.
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Same concept, more angles
1 more way this is tested on KCNA
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A DevOps team wants to adopt a deployment pattern where a new version of an application is gradually rolled out to a small subset of users before full deployment. Which progressive delivery technique should they use?
medium- ✓ A.Canary deployment
- B.Rolling update
- C.Blue-green deployment
- D.Recreate deployment
Why A: Canary deployment is the progressive delivery technique that routes a small percentage of live traffic to the new version while the majority continues to hit the stable version. This allows the team to observe real-user metrics (error rates, latency, business KPIs) on a limited blast radius before promoting the release to 100% of users. It is the canonical pattern for gradual, risk-controlled rollouts.
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.