Question 1120
At Northstar finance, in an isolated training cluster during a scheduled maintenance rehearsal: Node worker-a becomes NotReady and kubelet logs contain container runtime unavailable errors after a host patch. Work only within the stated target and verify before declaring success. Which operational control most directly prevents this failure or configuration drift?
Explanation
Correct Answer
Test kubelet/CRI version compatibility and runtime services in node patch runbooks. This reduces recurrence of the specific operational failure. It reinforces the action: On worker-a, run sudo systemctl status containerd and sudo journalctl -u containerd -n 80 --no-pager before modifying runtime configuration. The relevant mechanism is: Kubelet relies on a CRI-compatible runtime for container creation; restarting application Pods cannot repair an unavailable runtime.
Incorrect Answers
That safeguard is relevant to: Node readiness depends on the kubelet and node conditions; application restarts cannot fix a stopped kubelet service. The current failure instead follows from: Kubelet relies on a CRI-compatible runtime for container creation; restarting application Pods cannot repair an unavailable runtime. Its prevention measure is “Test kubelet/CRI version compatibility and runtime services in node patch runbooks”.
This routine guards against another mechanism: Node memory pressure can cause evictions and scheduling instability independent of one container's OOMKilled status. The recurring exposure in the current case is: Kubelet relies on a CRI-compatible runtime for container creation; restarting application Pods cannot repair an unavailable runtime. The matching preventive check is “Test kubelet/CRI version compatibility and runtime services in node patch runbooks”.
That safeguard is relevant to: DiskPressure is a node condition triggered by storage thresholds; deleting live runtime data blindly can corrupt workloads. The current failure instead follows from: Kubelet relies on a CRI-compatible runtime for container creation; restarting application Pods cannot repair an unavailable runtime. Its prevention measure is “Test kubelet/CRI version compatibility and runtime services in node patch runbooks”.