AWS::AutoScaling::AutoScalingGroup LaunchTemplateOverrides - AWS CloudFormation

AWS::AutoScaling::AutoScalingGroup LaunchTemplateOverrides

LaunchTemplateOverrides is a property of the AWS::AutoScaling::AutoScalingGroup LaunchTemplate property type that describes an override for a launch template.

If you supply your own instance types, the maximum number of instance types that can be associated with an Auto Scaling group is 40. The maximum number of distinct launch templates you can define for an Auto Scaling group is 20.

Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

Properties

InstanceRequirements

The instance requirements. When you specify instance requirements, Amazon EC2 Auto Scaling finds instance types that satisfy your requirements, and then uses your On-Demand and Spot allocation strategies to launch instances from these instance types, in the same way as when you specify a list of specific instance types.

Note

InstanceRequirements are incompatible with the InstanceType and WeightedCapacity properties.

Required: No

Type: InstanceRequirements

Update requires: No interruption

InstanceType

The instance type, such as m3.xlarge. You must use an instance type that is supported in your requested Region and Availability Zones. For more information, see Instance types in the Amazon Elastic Compute Cloud User Guide.

Required: No

Type: String

Update requires: No interruption

LaunchTemplateSpecification

Provides a launch template for the specified instance type or instance requirements. For example, some instance types might require a launch template with a different AMI. If not provided, Amazon EC2 Auto Scaling uses the launch template that's defined for your mixed instances policy. For more information, see Specifying a different launch template for an instance type in the Amazon EC2 Auto Scaling User Guide.

Required: No

Type: LaunchTemplateSpecification

Update requires: No interruption

WeightedCapacity

The number of capacity units provided by the instance type specified in InstanceType in terms of virtual CPUs, memory, storage, throughput, or other relative performance characteristic. When a Spot or On-Demand Instance is provisioned, the capacity units count toward the desired capacity. Amazon EC2 Auto Scaling provisions instances until the desired capacity is totally fulfilled, even if this results in an overage. For example, if there are 2 units remaining to fulfill capacity, and Amazon EC2 Auto Scaling can only provision an instance with a WeightedCapacity of 5 units, the instance is provisioned, and the desired capacity is exceeded by 3 units. For more information, see Configure instance weighting for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide. Value must be in the range of 1-999.

Important

Every Auto Scaling group has three size parameters (DesiredCapacity, MaxSize, and MinSize). Usually, you set these sizes based on a specific number of instances. However, if you configure a mixed instances policy that defines weights for the instance types, you must specify these sizes with the same units that you use for weighting instances.

Required: No

Type: String

Update requires: No interruption