Question 440
At Horizon observability, in a disposable simulated environment during a monitored release window: Deployment metrics-api in namespace observability should autoscale between 3 and 8 replicas at 70% CPU utilization with metrics API available. 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
Track HPA metric availability and avoid simultaneous manual scaling policies that fight the controller. This reduces recurrence of the specific operational failure. It reinforces the action: Run kubectl -n observability autoscale deployment metrics-api --cpu-percent=70 --min=3 --max=8 after setting valid CPU requests. The relevant mechanism is: HPA evaluates metrics relative to Pod resource requests; missing metrics or requests can leave desired replicas unknown.
Incorrect Answers
The suggested review tracks a different technical risk: A toleration allows a Pod past a matching taint but does not ensure placement without node selection and capacity. Here the sustained control must address: HPA evaluates metrics relative to Pod resource requests; missing metrics or requests can leave desired replicas unknown. Choose “Track HPA metric availability and avoid simultaneous manual scaling policies that fight the controller”.
That safeguard is relevant to: Deployment rolling-update parameters govern how many old Pods may be unavailable and extra Pods may be created during replacement. The current failure instead follows from: HPA evaluates metrics relative to Pod resource requests; missing metrics or requests can leave desired replicas unknown. Its prevention measure is “Track HPA metric availability and avoid simultaneous manual scaling policies that fight the controller”.
This routine guards against another mechanism: Scaling the Deployment changes desired replica count through its controller; editing an individual Pod would not preserve the desired state. The recurring exposure in the current case is: HPA evaluates metrics relative to Pod resource requests; missing metrics or requests can leave desired replicas unknown. The matching preventive check is “Track HPA metric availability and avoid simultaneous manual scaling policies that fight the controller”.