AWS - 2i2c Infrastructure Guide

eksctl creates nodepools that are mostly immutable, except for autoscaling properties - minimum and maximum number of nodes. In certain cases, it might be helpful to ‘scale up’ a nodegroup in a cluster before an event, to test cloud provider quotas or to make user server startup faster.

Open the appropriate .jsonnet file for the cluster in question (located in the eksctl folder). Depending on how you intend to scale the nodepools, there are two approaches you may take.
Scale the desired nodepool

Depending on which nodepool(s) you want to scale up, tweak the arguments of cluster.withNodeGroupConfigOverride to match your needs.

cluster.withNodeGroupConfigOverride(
   c,
   kind='notebook',
   instanceType='r5.4xlarge',
   hubName='prod',
   overrides={
      desiredCapacity: 10,
      minSize: 10,
   }
)

Where:

c is the cluster object created with cluster.makeCluster defined in eksctl/libsonnet/cluster.jsonnet
both minSize and desiredCapacity represent the number of nodes wanted in the nodepool

Tip

You can also chain multiple cluster.withNodeGroupConfigOverride for better matching of nodepools to scale.

cluster.withNodeGroupConfigOverride(
   cluster.withNodeGroupConfigOverride(
      c,
      kind='notebook',
      instanceType='r5.4xlarge',
      hubName='pythia-binder',
      overrides={
         desiredCapacity: 11,
         minSize: 11,
      }
   ),
   kind='notebook',
   instanceType='r5.4xlarge',
   hubName='prod',
   overrides={
      desiredCapacity: 11,
      minSize: 11,
   }
)

Render the .jsonnet file into a YAML file with:

export CLUSTER_NAME=<your_cluster>

jsonnet $CLUSTER_NAME.jsonnet > $CLUSTER_NAME.eksctl.yaml

Use eksctl to scale the cluster.
```
eksctl scale nodegroup --config-file=$CLUSTER_NAME.eksctl.yaml
```
Note
eksctl might print warning messages such as retryable error (Throttling: Rate exceeded. This is just a warning, and shouldn’t have any actual effects on the scaling operation except cause a delay.
Validate that appropriate new nodes are coming up by authenticating to the cluster, and running kubectl get node.
Commit the change and make a PR, and note that you have already completed the scaling operation. This is flexible, as the scaling operation might need to be timed differently in each case. The goal is to make sure that the minSize parameter in the github repository matches reality.