StepScalingPolicyConfiguration - Application Auto Scaling
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StepScalingPolicyConfiguration

Represents a step scaling policy configuration to use with Application Auto Scaling.

Contents

AdjustmentType

Specifies how the ScalingAdjustment value in a StepAdjustment is interpreted (for example, an absolute number or a percentage). The valid values are ChangeInCapacity, ExactCapacity, and PercentChangeInCapacity.

AdjustmentType is required if you are adding a new step scaling policy configuration.

Type: String

Valid Values: ChangeInCapacity | PercentChangeInCapacity | ExactCapacity

Required: No

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. The scaling policy won't increase the desired capacity again unless either a larger scale out is triggered or the cooldown period ends. 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 and entity recognizer endpoints

  • Lambda provisioned concurrency

  • Amazon Keyspaces tables

  • Amazon MSK broker storage

Type: Integer

Required: No

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.

Type: String

Valid Values: Average | Minimum | Maximum

Required: No

MinAdjustmentMagnitude

The minimum value to scale by when the adjustment type is PercentChangeInCapacity. 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.

Type: Integer

Required: No

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.

Type: Array of StepAdjustment objects

Required: No