AWS::ApplicationAutoScaling::ScalingPolicy StepScalingPolicyConfiguration - AWS CloudFormation

AWS::ApplicationAutoScaling::ScalingPolicy StepScalingPolicyConfiguration

StepScalingPolicyConfiguration is a property of ScalingPolicy that specifies a step scaling policy configuration to use with Application Auto Scaling.

For more information, see PutScalingPolicy in the Application Auto Scaling API Reference. For more information about step scaling policies, see Step scaling policies in the Application Auto Scaling User Guide.

Syntax

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

JSON

{ "AdjustmentType" : String, "Cooldown" : Integer, "MetricAggregationType" : String, "MinAdjustmentMagnitude" : Integer, "StepAdjustments" : [ StepAdjustment, ... ] }

Properties

AdjustmentType

Specifies whether the ScalingAdjustment value in the StepAdjustment property is an absolute number or a percentage of the current capacity.

Required: No

Type: String

Allowed values: ChangeInCapacity | ExactCapacity | PercentChangeInCapacity

Update requires: No interruption

Cooldown

The amount of time, in seconds, to wait for a previous scaling activity to take effect.

With scale-out policies, the intention is to continuously (but not excessively) scale out. After Application Auto Scaling successfully scales out using a step scaling policy, it starts to calculate the cooldown time. While the cooldown period is in effect, capacity added by the initiating scale-out activity is calculated as part of the desired capacity for the next scale-out activity. For example, when an alarm triggers a step scaling policy to increase the capacity by 2, the scaling activity completes successfully, and a cooldown period starts. If the alarm triggers again during the cooldown period but at a more aggressive step adjustment of 3, the previous increase of 2 is considered part of the current capacity. Therefore, only 1 is added to the capacity.

With scale-in policies, the intention is to scale in conservatively to protect your application’s availability, so scale-in activities are blocked until the cooldown period has expired. However, if another alarm triggers a scale-out activity during the cooldown period after a scale-in activity, Application Auto Scaling scales out the target immediately. In this case, the cooldown period for the scale-in activity stops and doesn't complete.

Application Auto Scaling provides a default value of 300 for the following scalable targets:

  • ECS services

  • Spot Fleet requests

  • EMR clusters

  • AppStream 2.0 fleets

  • Aurora DB clusters

  • Amazon SageMaker endpoint variants

  • Custom resources

For all other scalable targets, the default value is 0:

  • DynamoDB tables

  • DynamoDB global secondary indexes

  • Amazon Comprehend document classification endpoints

  • Lambda provisioned concurrency

  • Amazon Keyspaces tables

Required: No

Type: Integer

Update requires: No interruption

MetricAggregationType

The aggregation type for the CloudWatch metrics. Valid values are Minimum, Maximum, and Average. If the aggregation type is null, the value is treated as Average.

Required: No

Type: String

Allowed values: Average | Maximum | Minimum

Update requires: No interruption

MinAdjustmentMagnitude

The minimum value to scale by when scaling by percentages. For example, suppose that you create a step scaling policy to scale out an Amazon ECS service by 25 percent and you specify a MinAdjustmentMagnitude of 2. If the service has 4 tasks and the scaling policy is performed, 25 percent of 4 is 1. However, because you specified a MinAdjustmentMagnitude of 2, Application Auto Scaling scales out the service by 2 tasks.

Valid only if the adjustment type is PercentChangeInCapacity.

Required: No

Type: Integer

Update requires: No interruption

StepAdjustments

A set of adjustments that enable you to scale based on the size of the alarm breach.

At least one step adjustment is required if you are adding a new step scaling policy configuration.

Required: No

Type: List of StepAdjustment

Update requires: No interruption