This KCNA practice question tests your understanding of container orchestration. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 Deployment manages 3 replicas of a pod. During a rolling update, one of the new pods enters CrashLoopBackOff. What happens next?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The Deployment pauses the rollout and waits for manual intervention
Option D is correct because, by default, a Deployment's rolling update strategy has a `progressDeadlineSeconds` setting (default 600 seconds) and a `maxUnavailable`/`maxSurge` configuration. When a new pod enters CrashLoopBackOff, the Deployment's controller detects that the update is not making progress (the new ReplicaSet cannot reach the desired replica count with healthy pods). After the progress deadline expires, the Deployment marks the rollout as failed and pauses the update, requiring manual intervention (e.g., `kubectl rollout undo` or fixing the pod template). This behavior is governed by the Deployment controller's reconciliation loop and the `Progressing` condition.
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.
✗
The Deployment deletes all pods and recreates them
Why it's wrong here
That would cause downtime and is not default behavior.
✗
The Deployment automatically reverts to the previous ReplicaSet
Why it's wrong here
Auto-rollback is not default; it requires a Deployment with revisionHistoryLimit and manual rollback.
✗
The Deployment continues the rollout, ignoring the failure
Why it's wrong here
The Deployment will stop the rollout if the new pod is not healthy.
✓
The Deployment pauses the rollout and waits for manual intervention
Why this is correct
The Deployment controller will not proceed with the update if the new pod fails readiness checks.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
CNCF often tests the misconception that a Deployment automatically rolls back on failure, but in reality, it only pauses after a progress deadline, requiring manual rollback or correction.
Detailed technical explanation
How to think about this question
Under the hood, the Deployment controller uses a ReplicaSet for each revision. During a rolling update, it creates a new ReplicaSet and gradually scales it up while scaling down the old one, respecting `maxSurge` and `maxUnavailable`. The `progressDeadlineSeconds` field (default 600 seconds) sets a timeout for the rollout to make progress; if the new ReplicaSet fails to reach the desired number of healthy pods (e.g., due to CrashLoopBackOff), the Deployment sets the `Progressing` condition to `False` with reason `ProgressDeadlineExceeded`, effectively pausing the rollout. This prevents infinite retries and alerts the operator to intervene.
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 practitioner preparing for the KCNA exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this KCNA question in full detail.
Container Orchestration — This question tests Container Orchestration — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The Deployment pauses the rollout and waits for manual intervention — Option D is correct because, by default, a Deployment's rolling update strategy has a `progressDeadlineSeconds` setting (default 600 seconds) and a `maxUnavailable`/`maxSurge` configuration. When a new pod enters CrashLoopBackOff, the Deployment's controller detects that the update is not making progress (the new ReplicaSet cannot reach the desired replica count with healthy pods). After the progress deadline expires, the Deployment marks the rollout as failed and pauses the update, requiring manual intervention (e.g., `kubectl rollout undo` or fixing the pod template). This behavior is governed by the Deployment controller's reconciliation loop and the `Progressing` condition.
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.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.