The answer is to SSH into the worker node and run `kubeadm upgrade node`, then upgrade kubelet and kubectl, and finally restart the kubelet. This is correct because `kubeadm upgrade node` updates the node’s kubelet configuration and static pod manifests to match the new control plane version, but it does not automatically upgrade the kubelet binary itself—that requires a separate package manager step. On the CKA exam, this task tests your understanding that worker nodes are not upgraded by the control plane’s `kubeadm upgrade apply`; each node must be handled individually, and a common trap is forgetting to restart the kubelet after upgrading its binary. Remember the sequence: drain, upgrade config, upgrade binaries, restart kubelet, uncordon. A helpful mnemonic is “SSH, Node, Binary, Restart” to avoid missing the critical kubelet restart step.
CKA Practice Question: Cluster Architecture, Installation and Configuration
This CKA practice question tests your understanding of cluster architecture, installation and configuration. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 cluster was upgraded from v1.28 to v1.29 using kubeadm. After upgrading the control plane, nodes remain at v1.28. What is the correct next step to upgrade a worker node?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
SSH into the worker node and run 'kubeadm upgrade node', then upgrade kubelet and kubectl, then restart kubelet.
Option B is correct because after upgrading the control plane with kubeadm, worker nodes must be upgraded individually. The correct sequence is to SSH into the worker node, run 'kubeadm upgrade node' to upgrade the kubelet configuration and static pod manifests, then upgrade the kubelet and kubectl binaries (typically via the package manager), and finally restart the kubelet to pick up the new version. This ensures the node runs the same Kubernetes version as the control plane.
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.
✗
Drain the node, then run 'kubeadm upgrade node' on the worker node.
Why it's wrong here
Draining is recommended before upgrading, but the immediate next step is to run kubeadm upgrade node on the worker node itself.
✓
SSH into the worker node and run 'kubeadm upgrade node', then upgrade kubelet and kubectl, then restart kubelet.
Why this is correct
This is the standard procedure for upgrading a worker node with kubeadm.
Related concept
Read the scenario before looking for a memorised answer.
✗
Upgrade kubelet on the worker node using the package manager and restart kubelet.
Why it's wrong here
kubeadm must be upgraded first to ensure compatibility.
✗
Run 'kubeadm upgrade apply' on the worker node.
Why it's wrong here
kubeadm upgrade apply is only for the control plane, not worker nodes.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often assume simply upgrading the kubelet binary via the package manager is sufficient, but the CKA exam tests the understanding that 'kubeadm upgrade node' must be run first to update the node's configuration and static pod manifests, ensuring a complete and consistent upgrade.
Detailed technical explanation
How to think about this question
The 'kubeadm upgrade node' command on a worker node updates the kubelet configuration file (typically /var/lib/kubelet/config.yaml) and regenerates static pod manifests for control plane components if the node is a control plane node. For worker nodes, it primarily updates the kubelet configuration to match the new version's API. After this, upgrading the kubelet binary ensures the actual kubelet process runs the correct version, and restarting kubelet applies the changes. In real-world scenarios, failing to run 'kubeadm upgrade node' can cause the kubelet to use outdated configuration, leading to node registration failures or version skew issues.
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 CKA 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 CKA question in full detail.
Cluster Architecture, Installation and Configuration — This question tests Cluster Architecture, Installation and Configuration — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: SSH into the worker node and run 'kubeadm upgrade node', then upgrade kubelet and kubectl, then restart kubelet. — Option B is correct because after upgrading the control plane with kubeadm, worker nodes must be upgraded individually. The correct sequence is to SSH into the worker node, run 'kubeadm upgrade node' to upgrade the kubelet configuration and static pod manifests, then upgrade the kubelet and kubectl binaries (typically via the package manager), and finally restart the kubelet to pick up the new version. This ensures the node runs the same Kubernetes version as the control plane.
What should I do if I get this CKA 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 →
Why A: After upgrading kubeadm on the node, the correct command to upgrade the kubelet configuration is `kubeadm upgrade node config --kubelet-version v1.29.0`. This command updates the kubelet configuration file (typically `/var/lib/kubelet/config.yaml`) to match the target Kubernetes version, ensuring the kubelet can join the upgraded control plane. It is a specific subcommand of `kubeadm upgrade node` that handles only the kubelet configuration, not the kubelet binary itself.
Variation 2. You need to upgrade a Kubernetes cluster from v1.28 to v1.29 using kubeadm. After upgrading the control plane, what should you do on each worker node?
Why C: Option C is correct because the standard kubeadm upgrade workflow for worker nodes requires first draining the node to safely evict all pods, then running 'kubeadm upgrade node' to upgrade the kubelet and kube-proxy configuration, and finally uncordoning the node to make it schedulable again. This sequence ensures minimal disruption to workloads and follows the official Kubernetes upgrade documentation.
Variation 3. After upgrading the control plane using kubeadm, you need to update the kubelet configuration on the node. Which command should you run on the node?
medium
A.kubeadm upgrade apply
B.kubectl upgrade node
✓ C.kubeadm upgrade node
D.kubeadm upgrade plan
Why C: Option C is correct because `kubeadm upgrade node` is the command used on worker nodes (or secondary control-plane nodes) after the primary control plane has been upgraded. It upgrades the kubelet configuration and other node-specific components to match the new cluster version, ensuring the node can rejoin the upgraded cluster.
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This CKA 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 CKA exam.
Question Discussion
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