AWS::ApplicationAutoScaling::ScalingPolicy - AWS CloudFormation

AWS::ApplicationAutoScaling::ScalingPolicy

The AWS::ApplicationAutoScaling::ScalingPolicy resource defines a scaling policy that Application Auto Scaling uses to adjust your application resources.

For more information about Application Auto Scaling scaling policies, see the Application Auto Scaling User Guide.

Syntax

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

JSON

{ "Type" : "AWS::ApplicationAutoScaling::ScalingPolicy", "Properties" : { "PolicyName" : String, "PolicyType" : String, "ResourceId" : String, "ScalableDimension" : String, "ScalingTargetId" : String, "ServiceNamespace" : String, "StepScalingPolicyConfiguration" : StepScalingPolicyConfiguration, "TargetTrackingScalingPolicyConfiguration" : TargetTrackingScalingPolicyConfiguration } }

Properties

PolicyName

The name of the scaling policy.

Required: Yes

Type: String

Minimum: 1

Maximum: 256

Pattern: \p{Print}+

Update requires: Replacement

PolicyType

The Application Auto Scaling policy type.

The following policy types are supported:

TargetTrackingScaling—Not supported for Amazon EMR

StepScaling—Not supported for DynamoDB, Amazon Comprehend, Lambda, or Amazon Keyspaces (for Apache Cassandra)

Required: Yes

Type: String

Update requires: No interruption

ResourceId

The identifier of the resource associated with the scaling policy. This string consists of the resource type and unique identifier.

  • ECS service - The resource type is service and the unique identifier is the cluster name and service name. Example: service/default/sample-webapp.

  • Spot Fleet request - The resource type is spot-fleet-request and the unique identifier is the Spot Fleet request ID. Example: spot-fleet-request/sfr-73fbd2ce-aa30-494c-8788-1cee4EXAMPLE.

  • EMR cluster - The resource type is instancegroup and the unique identifier is the cluster ID and instance group ID. Example: instancegroup/j-2EEZNYKUA1NTV/ig-1791Y4E1L8YI0.

  • AppStream 2.0 fleet - The resource type is fleet and the unique identifier is the fleet name. Example: fleet/sample-fleet.

  • DynamoDB table - The resource type is table and the unique identifier is the table name. Example: table/my-table.

  • DynamoDB global secondary index - The resource type is index and the unique identifier is the index name. Example: table/my-table/index/my-table-index.

  • Aurora DB cluster - The resource type is cluster and the unique identifier is the cluster name. Example: cluster:my-db-cluster.

  • Amazon SageMaker endpoint variant - The resource type is variant and the unique identifier is the resource ID. Example: endpoint/my-end-point/variant/KMeansClustering.

  • Custom resources are not supported with a resource type. This parameter must specify the OutputValue from the CloudFormation template stack used to access the resources. The unique identifier is defined by the service provider. More information is available in our GitHub repository.

  • Amazon Comprehend document classification endpoint - The resource type and unique identifier are specified using the endpoint ARN. Example: arn:aws:comprehend:us-west-2:123456789012:document-classifier-endpoint/EXAMPLE.

  • Lambda provisioned concurrency - The resource type is function and the unique identifier is the function name with a function version or alias name suffix that is not $LATEST. Example: function:my-function:prod or function:my-function:1.

  • Amazon Keyspaces table - The resource type is table and the unique identifier is the table name. Example: keyspace/mykeyspace/table/mytable.

Required: No

Type: String

Minimum: 1

Maximum: 1600

Pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*

Update requires: Replacement

ScalableDimension

The scalable dimension. This string consists of the service namespace, resource type, and scaling property.

  • ecs:service:DesiredCount - The desired task count of an ECS service.

  • ec2:spot-fleet-request:TargetCapacity - The target capacity of a Spot Fleet request.

  • elasticmapreduce:instancegroup:InstanceCount - The instance count of an EMR Instance Group.

  • appstream:fleet:DesiredCapacity - The desired capacity of an AppStream 2.0 fleet.

  • dynamodb:table:ReadCapacityUnits - The provisioned read capacity for a DynamoDB table.

  • dynamodb:table:WriteCapacityUnits - The provisioned write capacity for a DynamoDB table.

  • dynamodb:index:ReadCapacityUnits - The provisioned read capacity for a DynamoDB global secondary index.

  • dynamodb:index:WriteCapacityUnits - The provisioned write capacity for a DynamoDB global secondary index.

  • rds:cluster:ReadReplicaCount - The count of Aurora Replicas in an Aurora DB cluster. Available for Aurora MySQL-compatible edition and Aurora PostgreSQL-compatible edition.

  • sagemaker:variant:DesiredInstanceCount - The number of EC2 instances for an Amazon SageMaker model endpoint variant.

  • custom-resource:ResourceType:Property - The scalable dimension for a custom resource provided by your own application or service.

  • comprehend:document-classifier-endpoint:DesiredInferenceUnits - The number of inference units for an Amazon Comprehend document classification endpoint.

  • lambda:function:ProvisionedConcurrency - The provisioned concurrency for a Lambda function.

  • cassandra:table:ReadCapacityUnits - The provisioned read capacity for an Amazon Keyspaces table.

  • cassandra:table:WriteCapacityUnits - The provisioned write capacity for an Amazon Keyspaces table.

Required: No

Type: String

Allowed values: appstream:fleet:DesiredCapacity | cassandra:table:ReadCapacityUnits | cassandra:table:WriteCapacityUnits | comprehend:document-classifier-endpoint:DesiredInferenceUnits | custom-resource:ResourceType:Property | dynamodb:index:ReadCapacityUnits | dynamodb:index:WriteCapacityUnits | dynamodb:table:ReadCapacityUnits | dynamodb:table:WriteCapacityUnits | ec2:spot-fleet-request:TargetCapacity | ecs:service:DesiredCount | elasticmapreduce:instancegroup:InstanceCount | lambda:function:ProvisionedConcurrency | rds:cluster:ReadReplicaCount | sagemaker:variant:DesiredInstanceCount

Update requires: Replacement

ScalingTargetId

The AWS CloudFormation-generated ID of an Application Auto Scaling scalable target. For more information about the ID, see the Return Value section of the AWS::ApplicationAutoScaling::ScalableTarget resource.

Important

You must specify either the ScalingTargetId property, or the ResourceId, ScalableDimension, and ServiceNamespace properties, but not both.

Required: Conditional

Type: String

Update requires: Replacement

ServiceNamespace

The namespace of the AWS service that provides the resource, or a custom-resource.

Required: No

Type: String

Allowed values: appstream | cassandra | comprehend | custom-resource | dynamodb | ec2 | ecs | elasticmapreduce | lambda | rds | sagemaker

Update requires: Replacement

StepScalingPolicyConfiguration

A step scaling policy.

Required: No

Type: StepScalingPolicyConfiguration

Update requires: No interruption

TargetTrackingScalingPolicyConfiguration

A target tracking scaling policy.

Required: No

Type: TargetTrackingScalingPolicyConfiguration

Update requires: No interruption

Return values

Ref

When the logical ID of this resource is provided to the Ref intrinsic function, Ref returns the Application Auto Scaling scaling policy Amazon Resource Name (ARN). For example: arn:aws:autoscaling:us-east-2:123456789012:scalingPolicy:12ab3c4d-56789-0ef1-2345-6ghi7jk8lm90:resource/ecs/service/ecsStack-MyECSCluster-AB12CDE3F4GH/ecsStack-MyECSService-AB12CDE3F4GH:policyName/MyStepPolicy.

For more information about using the Ref function, see Ref.

Examples

The following examples create scaling policies for a scalable target that is registered with Application Auto Scaling.

For more template snippets, see Application Auto Scaling template examples.

Target tracking scaling policy with a predefined metric

This example shows how to declare a new AWS::ApplicationAutoScaling::ScalingPolicy resource to create a new scaling policy using the TargetTrackingScaling policy type.

In this snippet, the policy specifies the ECSServiceAverageCPUUtilization predefined metric. The metrics used with a target tracking scaling policy are either custom or predefined. For the list of predefined metrics, see PredefinedMetricSpecification. When the metric is at or exceeds 75 percent, the scaling policy increases (scales out) the capacity of the scalable target, and when it falls below 75 percent, the scaling policy decreases (scales in) the capacity of the scalable target. The scaling policy has a 60 second cooldown period after every scaling activity.

JSON

{ "Resources":{ "TargetTrackingScalingPolicy":{ "Type":"AWS::ApplicationAutoScaling::ScalingPolicy", "Properties":{ "PolicyName":"cpu75-target-tracking-scaling-policy", "PolicyType":"TargetTrackingScaling", "ScalingTargetId":{ "Ref":"ScalableTarget" }, "TargetTrackingScalingPolicyConfiguration":{ "TargetValue":75.0, "ScaleInCooldown":60, "ScaleOutCooldown":60, "PredefinedMetricSpecification":{ "PredefinedMetricType":"ECSServiceAverageCPUUtilization" } } } } } }

YAML

--- Resources: TargetTrackingScalingPolicy: Type: AWS::ApplicationAutoScaling::ScalingPolicy Properties: PolicyName: cpu75-target-tracking-scaling-policy PolicyType: TargetTrackingScaling ScalingTargetId: !Ref ScalableTarget TargetTrackingScalingPolicyConfiguration: TargetValue: 75.0 ScaleInCooldown: 60 ScaleOutCooldown: 60 PredefinedMetricSpecification: PredefinedMetricType: ECSServiceAverageCPUUtilization

Step scaling policy

The following example creates a scaling policy with the StepScaling policy type and the ChangeInCapacity adjustment type. When an associated alarm is triggered, the policy increases the capacity of the scalable target based on the following step adjustments (assuming a CloudWatch alarm threshold of 70 percent):

  • Increase capacity by 1 when the value of the metric is greater than or equal to 70 percent but less than 85 percent

  • Increase capacity by 2 when the value of the metric is greater than or equal to 85 percent but less than 95 percent

  • Increase capacity by 3 when the value of the metric is greater than or equal to 95 percent

In this snippet, the scaling policy has a 600 second cooldown period after every scaling activity.

JSON

{ "Resources":{ "PolicyHigh":{ "Type":"AWS::ApplicationAutoScaling::ScalingPolicy", "Properties":{ "PolicyName":"PolicyHigh", "PolicyType":"StepScaling", "ScalingTargetId":{ "Ref":"ScalableTarget" }, "StepScalingPolicyConfiguration":{ "AdjustmentType":"ChangeInCapacity", "Cooldown":600, "MetricAggregationType":"Average", "StepAdjustments":[ { "MetricIntervalLowerBound":0, "MetricIntervalUpperBound":15, "ScalingAdjustment":1 }, { "MetricIntervalLowerBound":15, "MetricIntervalUpperBound":25, "ScalingAdjustment":2 }, { "MetricIntervalLowerBound":25, "ScalingAdjustment":3 } ] } } } } }

YAML

--- Resources: PolicyHigh: Type: AWS::ApplicationAutoScaling::ScalingPolicy Properties: PolicyName: PolicyHigh PolicyType: StepScaling ScalingTargetId: Ref: ScalableTarget StepScalingPolicyConfiguration: AdjustmentType: ChangeInCapacity Cooldown: 600 MetricAggregationType: Average StepAdjustments: - MetricIntervalLowerBound: 0 MetricIntervalUpperBound: 15 ScalingAdjustment: 1 - MetricIntervalLowerBound: 15 MetricIntervalUpperBound: 25 ScalingAdjustment: 2 - MetricIntervalLowerBound: 25 ScalingAdjustment: 3

See also