Syntax Properties Return values Remarks Examples See also

AWS::ApplicationAutoScaling::ScalingPolicy

The AWS::ApplicationAutoScaling::ScalingPolicy resource defines a scaling policy that Application Auto Scaling uses to adjust the capacity of a scalable target.

For more information, see Target tracking scaling policies and 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


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

YAML


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.

Updates to the name of a target tracking scaling policy are not supported, unless you also update the metric used for scaling. To change only a target tracking scaling policy's name, first delete the policy by removing the existing AWS::ApplicationAutoScaling::ScalingPolicy resource from the template and updating the stack. Then, recreate the resource with the same settings and a different name.

Required: Yes

Type: String

Minimum: 1

Maximum: 256

Pattern: \p{Print}+

Update requires: Replacement

PolicyType

The scaling policy type.

The following policy types are supported:

TargetTrackingScaling—Not supported for Amazon EMR

StepScaling—Not supported for DynamoDB, Amazon Comprehend, Lambda, Amazon Keyspaces, Amazon MSK, Amazon ElastiCache, or Neptune.

Required: Yes

Type: String

Allowed values: StepScaling | TargetTrackingScaling

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 - 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.
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.
Amazon Comprehend entity recognizer endpoint - The resource type and unique identifier are specified using the endpoint ARN. Example: arn:aws:comprehend:us-west-2:123456789012:entity-recognizer-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.
Amazon MSK cluster - The resource type and unique identifier are specified using the cluster ARN. Example: arn:aws:kafka:us-east-1:123456789012:cluster/demo-cluster-1/6357e0b2-0e6a-4b86-a0b4-70df934c2e31-5.
Amazon ElastiCache replication group - The resource type is replication-group and the unique identifier is the replication group name. Example: replication-group/mycluster.
Neptune cluster - The resource type is cluster and the unique identifier is the cluster name. Example: cluster:mycluster.

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.
elasticmapreduce:instancegroup:InstanceCount - The instance count of an EMR Instance Group.
ec2:spot-fleet-request:TargetCapacity - The target capacity of a Spot Fleet.
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 a 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.
comprehend:entity-recognizer-endpoint:DesiredInferenceUnits - The number of inference units for an Amazon Comprehend entity recognizer 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.
kafka:broker-storage:VolumeSize - The provisioned volume size (in GiB) for brokers in an Amazon MSK cluster.
elasticache:replication-group:NodeGroups - The number of node groups for an Amazon ElastiCache replication group.
elasticache:replication-group:Replicas - The number of replicas per node group for an Amazon ElastiCache replication group.
neptune:cluster:ReadReplicaCount - The count of read replicas in an Amazon Neptune DB cluster.

Required: No

Type: String

Update requires: Replacement

ScalingTargetId

The 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

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.

Remarks

When you create the AWS::CloudWatch::Alarm resource for a step scaling policy, specify the name of the scaling policy in the AlarmActions property. For a sample template snippet, see Amazon Elastic Container Service template snippets.

Examples

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

For more sample 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.

For more information, see Target tracking scaling policies in the Application Auto Scaling User Guide.

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.

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

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