This KCNA practice question tests your understanding of kubernetes fundamentals. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A user wants to ensure that a Deployment undergoes a rolling update with zero downtime, and that new Pods are fully ready before old Pods are terminated. Which field in the Deployment spec controls this behavior?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
spec.strategy.rollingUpdate.maxUnavailable and maxSurge
Option B is correct because `spec.strategy.rollingUpdate.maxUnavailable` and `maxSurge` control how many Pods can be unavailable and how many can be created above the desired count during a rolling update. Setting `maxUnavailable=0` ensures no old Pods are terminated until new Pods are fully ready, achieving zero-downtime updates. `maxSurge` allows extra Pods to be created before old ones are removed, enabling a controlled rollout.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
spec.minReadySeconds
Why it's wrong here
minReadySeconds specifies how long a newly created Pod should be ready before it is considered available.
✓
spec.strategy.rollingUpdate.maxUnavailable and maxSurge
Why this is correct
These fields control how many Pods can be unavailable and how many can be created above the desired count during a rolling update.
Related concept
Read the scenario before looking for a memorised answer.
✗
spec.replicas
Why it's wrong here
Replicas sets the desired number of Pods, but does not control update behavior.
✗
spec.template.spec.containers[].resources
Why it's wrong here
Resource requests and limits affect scheduling and limits, but not the update strategy.
Common exam traps
Common exam trap: answer the scenario, not the keyword
CNCF often tests the misconception that `minReadySeconds` controls the rolling update order, but it only affects the Pod's availability status after readiness, not the termination timing of old Pods.
Detailed technical explanation
How to think about this question
Under the hood, the Deployment controller uses a ReplicaSet to manage Pods; during a rolling update, it creates a new ReplicaSet and scales it up while scaling down the old one. The `maxSurge` field (default 25%) allows the new ReplicaSet to exceed the desired replica count, and `maxUnavailable` (default 25%) controls how many Pods can be unavailable relative to the desired count. Setting `maxUnavailable=0` forces the controller to wait for new Pods to pass readiness probes before terminating any old Pods, ensuring zero downtime in production traffic.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this KCNA question in full detail.
Kubernetes Fundamentals — This question tests Kubernetes Fundamentals — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: spec.strategy.rollingUpdate.maxUnavailable and maxSurge — Option B is correct because `spec.strategy.rollingUpdate.maxUnavailable` and `maxSurge` control how many Pods can be unavailable and how many can be created above the desired count during a rolling update. Setting `maxUnavailable=0` ensures no old Pods are terminated until new Pods are fully ready, achieving zero-downtime updates. `maxSurge` allows extra Pods to be created before old ones are removed, enabling a controlled rollout.
What should I do if I get this KCNA question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Question Discussion
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