- A
2 pods running
Before node failure: old ReplicaSet scaled down to 1, new up to 2 (total 3). Node failure kills the old pod, leaving 2 new pods running.
- B
4 pods running
Why wrong: 4 would be the maximum allowed by maxSurge=1, but the controller would not keep both old and new at full count simultaneously during update.
- C
3 pods running
Why wrong: 3 would be the initial count; after update and failure, only 2 remain.
- D
1 pod running
Why wrong: The new ReplicaSet has 2 pods; the old had 1 left before failure, but after failure, only the 2 new pods remain.
Question 604 of 997
Rolling Update with Node Failure: Pod Count After Failure
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. A key principle to apply: rollingUpdate. 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 developer creates a Deployment with replicas: 3 and strategy type: RollingUpdate with maxSurge: 1 and maxUnavailable: 1. During a rolling update, the Deployment controller creates a new ReplicaSet. After the new ReplicaSet has 2 pods ready, the node running one of the original ReplicaSet's pods fails. What is the MOST likely number of total pods running after the node failure, assuming no other actions?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"most likely"Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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
✓
2 pods running
Initially, the Deployment has 3 old pods. The rolling update starts: with maxSurge=1, the controller creates a new pod. Once it's ready, it terminates one old pod to keep desired replicas at 3. Then it creates another new pod. After the second new pod is ready, it terminates a second old pod. At this point, the new ReplicaSet has 2 ready pods, and the old ReplicaSet has only 1 pod remaining. The node running that last old pod fails, killing it. Thus, only the 2 new pods are running, giving a total of 2 pods.
Key principle: RollingUpdate
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
2 pods running
Why this is correct
Before node failure: old ReplicaSet scaled down to 1, new up to 2 (total 3). Node failure kills the old pod, leaving 2 new pods running.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
RollingUpdate
- ✗
4 pods running
Why it's wrong here
4 would be the maximum allowed by maxSurge=1, but the controller would not keep both old and new at full count simultaneously during update.
- ✗
3 pods running
Why it's wrong here
3 would be the initial count; after update and failure, only 2 remain.
- ✗
1 pod running
Why it's wrong here
The new ReplicaSet has 2 pods; the old had 1 left before failure, but after failure, only the 2 new pods remain.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Candidates often forget that the node failure creates an extra unavailable pod, exceeding maxUnavailable=1. This triggers the controller to scale down the remaining old pod to satisfy the constraint, even though it is still running. They may incorrectly count 3 pods (2 new + 1 old) as the final number.
Detailed technical explanation
How to think about this question
The Deployment controller uses ReplicaSets to manage pod creation and deletion during rolling updates. With maxSurge: 1, the controller can create one extra pod beyond the desired count (3), and with maxUnavailable: 1, it ensures at most one pod is unavailable during the update. When a node fails, the kubelet on that node is unreachable, and the pod is marked as Unknown, then eventually deleted by the node controller after a timeout (default 5 minutes). The Deployment controller does not immediately replace the pod because maxUnavailable: 1 is already satisfied by the rolling update's intentional unavailability, and the surge limit prevents creating additional pods beyond the desired count.
KKey Concepts to Remember
- RollingUpdate
- maxUnavailable
- maxSurge
- Rolling update process
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
RollingUpdate
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. RollingUpdate Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Review rollingUpdate, then practise related KCNA questions on the same topic to reinforce the concept.
- →
Container Orchestration — study guide chapter
Learn the concepts, then practise the questions
- →
Container Orchestration practice questions
Targeted practice on this topic area only
- →
All KCNA questions
997 questions across all exam domains
- →
Kubernetes and Cloud Native Associate KCNA study guide
Full concept coverage aligned to exam objectives
- →
KCNA practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related KCNA practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Kubernetes Fundamentals practice questions
Practise KCNA questions linked to Kubernetes Fundamentals.
Container Orchestration practice questions
Practise KCNA questions linked to Container Orchestration.
Cloud Native Architecture practice questions
Practise KCNA questions linked to Cloud Native Architecture.
Cloud Native Observability practice questions
Practise KCNA questions linked to Cloud Native Observability.
Cloud Native Application Delivery practice questions
Practise KCNA questions linked to Cloud Native Application Delivery.
KCNA fundamentals practice questions
Practise KCNA questions linked to KCNA fundamentals.
KCNA scenario practice questions
Practise KCNA questions linked to KCNA scenario.
KCNA troubleshooting practice questions
Practise KCNA questions linked to KCNA troubleshooting.
Practice this exam
Start a free KCNA practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this KCNA question test?
Container Orchestration — This question tests Container Orchestration — RollingUpdate.
What is the correct answer to this question?
The correct answer is: 2 pods running — Initially, the Deployment has 3 old pods. The rolling update starts: with maxSurge=1, the controller creates a new pod. Once it's ready, it terminates one old pod to keep desired replicas at 3. Then it creates another new pod. After the second new pod is ready, it terminates a second old pod. At this point, the new ReplicaSet has 2 ready pods, and the old ReplicaSet has only 1 pod remaining. The node running that last old pod fails, killing it. Thus, only the 2 new pods are running, giving a total of 2 pods.
What should I do if I get this KCNA question wrong?
Review rollingUpdate, then practise related KCNA questions on the same topic to reinforce the concept.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
RollingUpdate
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 →
Keep practising
More KCNA practice questions
- Which CNCF project provides a graduated service mesh implementation that includes features like traffic management, secu…
- A pod in the 'production' namespace is in a CrashLoopBackOff state. The pod has been running successfully for several da…
- You need to ensure that a pod runs on a node with SSD storage. How can you achieve this?
- Match each Kubernetes resource to its primary purpose.
- Match each Kubernetes security concept to its definition.
- Which three of the following are valid methods to create or update resources in Kubernetes? (Choose three.)
Last reviewed: Jul 4, 2026
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.