# Create a NodePool
<a name="sagemaker-hyperpod-eks-autoscaling-nodepool"></a>

The `NodePool` sets constraints on the nodes that can be created by Karpenter and the pods that can run on those nodes. The `NodePool` can be configured to do things like:
+ Limit node creation to certain zones, instance types, and computer architectures.
+ Define labels or taints to limit the pods that can run on nodes Karpenter creates.

**Note**  
HyperPod provider supports a limited set of well-known Kubernetes and Karpenter requirements explained below. 

The following steps cover how to create a `NodePool`.

1. Create a YAML file named nodepool.yaml with your desired `NodePool` configuration.

1. You can use the sample configuration below.

   Look for `Ready` under `Conditions` to indicate all dependent resources are functioning properly.

   ```
   apiVersion: karpenter.sh/v1
   kind: NodePool
   metadata:
    name: sample-np
   spec:
    template:
      spec:
        nodeClassRef:
         group: karpenter.sagemaker.amazonaws.com
         kind: HyperpodNodeClass
         name: multiazc5
        expireAfter: Never
        requirements:
           - key: node.kubernetes.io/instance-type
             operator: Exists
   ```

1. Apply the `NodePool` to your cluster:

   ```
   kubectl apply -f nodepool.yaml
   ```

1. Monitor the `NodePool` status to ensure the `Ready` condition in status is set to `True`:

   ```
   kubectl get nodepool sample-np -oyaml
   ```

   ```
   apiVersion: karpenter.sh/v1
   kind: NodePool
   metadata:
     name: <nodepool-name>
     uid: <resource-uid>
     ...
   spec:
     disruption:
       budgets:
       - nodes: 90%
       consolidateAfter: 0s
       consolidationPolicy: WhenEmptyOrUnderutilized
     template:
       spec:
         expireAfter: 720h
         nodeClassRef:
           group: karpenter.sagemaker.amazonaws.com
           kind: HyperpodNodeClass
           name: <nodeclass-name>
         requirements:
         - key: node.kubernetes.io/instance-type
           operator: Exists
   status:
     conditions:
     - lastTransitionTime: "<timestamp>"
       message: ""
       observedGeneration: 2
       reason: ValidationSucceeded
       status: "True"
       type: ValidationSucceeded
     - lastTransitionTime: "<timestamp>"
       message: ""
       observedGeneration: 2
       reason: NodeClassReady
       status: "True"
       type: NodeClassReady
     - lastTransitionTime: "<timestamp>"
       message: ""
       observedGeneration: 2
       reason: Ready
       status: "True"
       type: Ready
   ```

**Supported Labels for Karpenter HyperPod Provider**

These are the optional constraints and requirements you can specify in your `NodePool` configuration.


|  Requirement Type  |  Purpose  |  Use Case/Supported Values  |  Recommendation  | 
| --- | --- | --- | --- | 
|  Instance Types (`node.kubernetes.io/instance-type`)  |  Controls which SageMaker instance types Karpenter can choose from  |  Instead of restricting to only ml.c5.xlarge, let Karpenter pick from all available types in your instance groups  |  Leave this undefined or use Exists operator to give Karpenter maximum flexibility in choosing cost-effective instance types  | 
|  Availability Zones (`topology.kubernetes.io/zone`)  |  Controls which AWS availability zones nodes can be created in  |  Specific zone names like us-east-1c. Use when you need pods to run in specific zones for latency or compliance reasons  | n/a | 
|  Architecture (`kubernetes.io/arch`)  |  Specifies CPU architecture  |  Only amd64 (no ARM support currently)  |  n/a  |