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I have a EKS cluster running with cluster-autoscaler version 1.21.2 deployed. When I did a kubectl top nodes, I found a node using 5% cpu and 21% memory utilised. But in cluster-autoscaler pod log, I see below message for the same node: Node XXXX is not suitable for removal - cpu utilization too big (0.663130)

I'm now confused how is cluster autoscaler calculating this value and why is the node not scaled down. BTW, I used default config of --scale-down-utilization-threshold=0.5

Avanth Aditya
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1 Answers1

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We stumbled upon the same issue, and realized that the CPU utilization value (in your case 66,31%) matches roughly the amount of CPU requested by the pods/containers running on the node.

Remember: Requested CPU (and other resources) by a pod/container is given guaranteed.

This is why it sounds logical to us that when looking at the node's actual CPU usage, it might be idle, though from a Kubernetes autoscaling perspective, the node uses 66% from the CPU.

Dennis van de Hoef - Xiotin
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