Spot instances

eksctl has support for spot instances through the MixedInstancesPolicy for Auto Scaling Groups.

Here is an example of a nodegroup that uses 50% spot instances and 50% on demand instances:

nodeGroups:
  - name: ng-1
    minSize: 2
    maxSize: 5
    instancesDistribution:
      maxPrice: 0.017
      instanceTypes: ["t3.small", "t3.medium"] # At least one instance type should be specified
      onDemandBaseCapacity: 0
      onDemandPercentageAboveBaseCapacity: 50
      spotInstancePools: 2

Note that the nodeGroups.X.instanceType field shouldn't be set when using the instancesDistribution field.

This example uses GPU instances:

nodeGroups:
  - name: ng-gpu
    instanceType: mixed
    desiredCapacity: 1
    instancesDistribution:
      instanceTypes:
        - p2.xlarge
        - p2.8xlarge
        - p2.16xlarge
      maxPrice: 0.50

This example uses the capacity-optimized spot allocation strategy:

nodeGroups:
  - name: ng-capacity-optimized
    minSize: 2
    maxSize: 5
    instancesDistribution:
      maxPrice: 0.017
      instanceTypes: ["t3.small", "t3.medium"] # At least one instance type should be specified
      onDemandBaseCapacity: 0
      onDemandPercentageAboveBaseCapacity: 50
      spotAllocationStrategy: "capacity-optimized"

Note that the spotInstancePools field shouldn't be set when using the spotAllocationStrategy field. If the spotAllocationStrategy is not specified, EC2 will default to use the lowest-price strategy.

Here is a minimal example:

nodeGroups:
  - name: ng-1
    instancesDistribution:
      instanceTypes: ["t3.small", "t3.medium"] # At least one instance type should be specified

Parameters in instancesDistribution

Please see the config parameters for details.