class Aws::AutoScaling::Types::InstancesDistribution

Describes an instances distribution for an Auto Scaling group with a MixedInstancesPolicy.

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.

When you modify `SpotAllocationStrategy`, `SpotInstancePools`, or `SpotMaxPrice` in the UpdateAutoScalingGroup API call, this update action does not deploy any changes across the running Amazon EC2 instances in the group. Your existing Spot Instances continue to run as long as the maximum price for those instances is higher than the current Spot price. When scale out occurs, Amazon EC2 Auto Scaling launches instances based on the new settings. When scale in occurs, Amazon EC2 Auto Scaling terminates instances according to the group's termination policies.

@note When making an API call, you may pass InstancesDistribution

data as a hash:

    {
      on_demand_allocation_strategy: "XmlString",
      on_demand_base_capacity: 1,
      on_demand_percentage_above_base_capacity: 1,
      spot_allocation_strategy: "XmlString",
      spot_instance_pools: 1,
      spot_max_price: "MixedInstanceSpotPrice",
    }

@!attribute [rw] 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. This strategy uses the order of instance types in the
`LaunchTemplateOverrides` to define the launch priority of each
instance type. The first instance type in the array is prioritized
higher than the last. If all your On-Demand capacity cannot be
fulfilled using your highest priority instance, then the Auto
Scaling groups launches the remaining capacity using the second
priority instance type, and so on.
@return [String]

@!attribute [rw] 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.
@return [Integer]

@!attribute [rw] 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.
@return [Integer]

@!attribute [rw] spot_allocation_strategy

Indicates how to allocate instances across Spot Instance pools.

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.
@return [String]

@!attribute [rw] spot_instance_pools

The number of Spot Instance pools across which to allocate your Spot
Instances. 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.
@return [Integer]

@!attribute [rw] 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.
@return [String]

@see docs.aws.amazon.com/goto/WebAPI/autoscaling-2011-01-01/InstancesDistribution AWS API Documentation

Constants

SENSITIVE