Documentation

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

See: newStepScalingPolicyConfiguration smart constructor.

Create a value of StepScalingPolicyConfiguration with all optional fields omitted.

Use generic-lens or optics to modify other optional fields.

The following record fields are available, with the corresponding lenses provided for backwards compatibility:

$sel:stepAdjustments:StepScalingPolicyConfiguration', stepScalingPolicyConfiguration_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.

$sel:adjustmentType:StepScalingPolicyConfiguration', stepScalingPolicyConfiguration_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.

$sel:cooldown:StepScalingPolicyConfiguration', stepScalingPolicyConfiguration_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 600 for Amazon ElastiCache replication groups and a default value of 300 for the following scalable targets:

• AppStream 2.0 fleets
• Aurora DB clusters
• ECS services
• EMR clusters
• Neptune clusters
• SageMaker endpoint variants
• Spot Fleets
• Custom resources

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

• Amazon Comprehend document classification and entity recognizer endpoints
• DynamoDB tables and global secondary indexes
• Amazon Keyspaces tables
• Lambda provisioned concurrency
• Amazon MSK broker storage

$sel:metricAggregationType:StepScalingPolicyConfiguration', stepScalingPolicyConfiguration_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.

$sel:minAdjustmentMagnitude:StepScalingPolicyConfiguration', stepScalingPolicyConfiguration_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.

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.

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.

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 600 for Amazon ElastiCache replication groups and a default value of 300 for the following scalable targets:

• AppStream 2.0 fleets
• Aurora DB clusters
• ECS services
• EMR clusters
• Neptune clusters
• SageMaker endpoint variants
• Spot Fleets
• Custom resources

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

• Amazon Comprehend document classification and entity recognizer endpoints
• DynamoDB tables and global secondary indexes
• Amazon Keyspaces tables
• Lambda provisioned concurrency
• Amazon MSK broker storage

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.

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.