I am using EKS with node group for K8S.
The desired node is 1 and the maximum is 3.

Currently, there is only one ec2 (t3.xlarge) is running.
When I deploy two pods in one namespace, each requests 8G memory and 2 CPU, the first one is deployed successfully but the second one failed with the error 1 Insufficient cpu, 1 Insufficient memory.

I expect EKS should scale up one more node to allocate this new pod but it doesn't.
Does anyone know why the auto-scale doesn't happen? What am I understand wrong?

CodePudding user response：

With Amazon EKS you need to follow those rules prior to use AutoScaler

https://docs.aws.amazon.com/eks/latest/userguide/cluster-autoscaler.html

From the Official Docs above:

I have highlighted what might be your problem

Prerequisites

• Before deploying the Cluster Autoscaler, you must meet the following prerequisites:

• Have an existing Amazon EKS cluster – If you don’t have a cluster, see Creating an Amazon EKS cluster.

• An existing IAM OIDC provider for your cluster. To determine whether you have one or need to create one, see Create an IAM OIDC provider for your cluster.

• Node groups with Auto Scaling groups tags – The Cluster Autoscaler requires the following tags on your Auto Scaling groups so that they can be auto-discovered.

• If you used eksctl to create your node groups, these tags are automatically applied.

• If you didn't use eksctl, you must manually tag your Auto Scaling groups with the following tags.

  Key	Value
  k8s.io/cluster-autoscaler/	owned
  k8s.io/cluster-autoscaler/enabled	TRUE