InstancesDistribution

class aws_cdk.aws_autoscaling.InstancesDistribution(*, on_demand_allocation_strategy=None, on_demand_base_capacity=None, on_demand_percentage_above_base_capacity=None, spot_allocation_strategy=None, spot_instance_pools=None, spot_max_price=None)

Bases: object

InstancesDistribution is a subproperty of MixedInstancesPolicy that describes an instances distribution for an Auto Scaling group.

The instances distribution specifies the distribution of On-Demand Instances and Spot Instances, the maximum price to pay for Spot Instances, and how the Auto Scaling group allocates instance types to fulfill On-Demand and Spot capacities.

For more information and example configurations, see Auto Scaling groups with multiple instance types and purchase options in the Amazon EC2 Auto Scaling User Guide:

https://docs.aws.amazon.com/autoscaling/ec2/userguide/asg-purchase-options.html

Parameters
  • on_demand_allocation_strategy (Optional[OnDemandAllocationStrategy]) – Indicates how to allocate instance types to fulfill On-Demand capacity. The only valid value is prioritized, which is also the default value. Default: OnDemandAllocationStrategy.PRIORITIZED

  • on_demand_base_capacity (Union[int, float, None]) – The minimum amount of the Auto Scaling group’s capacity that must be fulfilled by On-Demand Instances. This base portion is provisioned first as your group scales. Defaults to 0 if not specified. If you specify weights for the instance types in the overrides, set the value of OnDemandBaseCapacity in terms of the number of capacity units, and not the number of instances. Default: 0

  • on_demand_percentage_above_base_capacity (Union[int, float, None]) – Controls the percentages of On-Demand Instances and Spot Instances for your additional capacity beyond OnDemandBaseCapacity. Expressed as a number (for example, 20 specifies 20% On-Demand Instances, 80% Spot Instances). Defaults to 100 if not specified. If set to 100, only On-Demand Instances are provisioned. Default: 100

  • spot_allocation_strategy (Optional[SpotAllocationStrategy]) – If the allocation strategy is lowest-price, the Auto Scaling group launches instances using the Spot pools with the lowest price, and evenly allocates your instances across the number of Spot pools that you specify. Defaults to lowest-price if not specified. If the allocation strategy is capacity-optimized (recommended), the Auto Scaling group launches instances using Spot pools that are optimally chosen based on the available Spot capacity. Alternatively, you can use capacity-optimized-prioritized and set the order of instance types in the list of launch template overrides from highest to lowest priority (from first to last in the list). Amazon EC2 Auto Scaling honors the instance type priorities on a best-effort basis but optimizes for capacity first. Default: SpotAllocationStrategy.LOWEST_PRICE

  • spot_instance_pools (Union[int, float, None]) – The number of Spot Instance pools to use to allocate your Spot capacity. The Spot pools are determined from the different instance types in the overrides. Valid only when the Spot allocation strategy is lowest-price. Value must be in the range of 1 to 20. Defaults to 2 if not specified. Default: 2

  • spot_max_price (Optional[str]) – The maximum price per unit hour that you are willing to pay for a Spot Instance. If you leave the value at its default (empty), Amazon EC2 Auto Scaling uses the On-Demand price as the maximum Spot price. To remove a value that you previously set, include the property but specify an empty string (“”) for the value. Default: “” - On-Demand price

ExampleMetadata

infused

Example:

# vpc: ec2.Vpc
# launch_template1: ec2.LaunchTemplate
# launch_template2: ec2.LaunchTemplate


autoscaling.AutoScalingGroup(self, "ASG",
    vpc=vpc,
    mixed_instances_policy=autoscaling.MixedInstancesPolicy(
        instances_distribution=autoscaling.InstancesDistribution(
            on_demand_percentage_above_base_capacity=50
        ),
        launch_template=launch_template1,
        launch_template_overrides=[autoscaling.LaunchTemplateOverrides(instance_type=ec2.InstanceType("t3.micro")), autoscaling.LaunchTemplateOverrides(instance_type=ec2.InstanceType("t3a.micro")), autoscaling.LaunchTemplateOverrides(instance_type=ec2.InstanceType("t4g.micro"), launch_template=launch_template2)]
    )
)

Attributes

on_demand_allocation_strategy

Indicates how to allocate instance types to fulfill On-Demand capacity.

The only valid value is prioritized, which is also the default value.

Default

OnDemandAllocationStrategy.PRIORITIZED

Return type

Optional[OnDemandAllocationStrategy]

on_demand_base_capacity

The minimum amount of the Auto Scaling group’s capacity that must be fulfilled by On-Demand Instances.

This base portion is provisioned first as your group scales. Defaults to 0 if not specified. If you specify weights for the instance types in the overrides, set the value of OnDemandBaseCapacity in terms of the number of capacity units, and not the number of instances.

Default

0

Return type

Union[int, float, None]

on_demand_percentage_above_base_capacity

Controls the percentages of On-Demand Instances and Spot Instances for your additional capacity beyond OnDemandBaseCapacity.

Expressed as a number (for example, 20 specifies 20% On-Demand Instances, 80% Spot Instances). Defaults to 100 if not specified. If set to 100, only On-Demand Instances are provisioned.

Default

100

Return type

Union[int, float, None]

spot_allocation_strategy

If the allocation strategy is lowest-price, the Auto Scaling group launches instances using the Spot pools with the lowest price, and evenly allocates your instances across the number of Spot pools that you specify.

Defaults to lowest-price if not specified.

If the allocation strategy is capacity-optimized (recommended), the Auto Scaling group launches instances using Spot pools that are optimally chosen based on the available Spot capacity. Alternatively, you can use capacity-optimized-prioritized and set the order of instance types in the list of launch template overrides from highest to lowest priority (from first to last in the list). Amazon EC2 Auto Scaling honors the instance type priorities on a best-effort basis but optimizes for capacity first.

Default

SpotAllocationStrategy.LOWEST_PRICE

Return type

Optional[SpotAllocationStrategy]

spot_instance_pools

The number of Spot Instance pools to use to allocate your Spot capacity.

The Spot pools are determined from the different instance types in the overrides. Valid only when the Spot allocation strategy is lowest-price. Value must be in the range of 1 to 20. Defaults to 2 if not specified.

Default

2

Return type

Union[int, float, None]

spot_max_price

The maximum price per unit hour that you are willing to pay for a Spot Instance.

If you leave the value at its default (empty), Amazon EC2 Auto Scaling uses the On-Demand price as the maximum Spot price. To remove a value that you previously set, include the property but specify an empty string (“”) for the value.

Default

“” - On-Demand price

Return type

Optional[str]