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AWS CloudFormation
User Guide (API Version 2010-05-15)

AWS Documentation » AWS CloudFormation » User Guide » Template Reference » AWS Resource Types Reference » AWS::ApplicationAutoScaling::ScalingPolicy

AWS::ApplicationAutoScaling::ScalingPolicy

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

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

A name for the scaling policy.

Required: Yes

Type: String

Update requires: Replacement

PolicyType

An Application Auto Scaling policy type.

Note

For DynamoDB, only TargetTrackingScaling is supported. For any other service, only StepScaling is supported.

Required: Yes

Type: String

Update requires: No interruption

ResourceId

The unique resource identifier for the scalable target that this scaling policy applies to. For more information, see the ResourceId parameter for the PutScalingPolicy action in the Application Auto Scaling API Reference.

Required: Conditional. You must specify either the ScalingTargetId property or the ResourceId, ScalableDimension, and ServiceNamespace properties. If you specify the ResourceId, ScalableDimension, and ServiceNamespace properties, don't specify the ScalingTargetId property.

Type: String

Update requires: Replacement

ScalableDimension

The scalable dimension of the scalable target that this scaling policy applies to. The scalable dimension contains the service namespace, resource type, and scaling property, such as ecs:service:DesiredCount for the desired task count of an Amazon ECS service.

Required: Conditional. You must specify either the ScalingTargetId property or the ResourceId, ScalableDimension, and ServiceNamespace properties. If you specify the ResourceId, ScalableDimension, and ServiceNamespace properties, don't specify the ScalingTargetId property.

Type: String

Update requires: Replacement

ServiceNamespace

The AWS service namespace of the scalable target that this scaling policy applies to. For a list of service namespaces, see AWS Service Namespaces in the AWS General Reference.

Required: Conditional. You must specify either the ScalingTargetId property or the ResourceId, ScalableDimension, and ServiceNamespace properties. If you specify the ResourceId, ScalableDimension, and ServiceNamespace properties, don't specify the ScalingTargetId property.

Type: String

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.

Required: Conditional. You must specify either the ScalingTargetId property or the ResourceId, ScalableDimension, and ServiceNamespace properties. If you specify this property, don't specify the ResourceId, ScalableDimension, and ServiceNamespace properties.

Type: String

Update requires: Replacement

StepScalingPolicyConfiguration

A step policy that configures when Application Auto Scaling scales resources up or down, and by how much.

Required: No

Type: Application Auto Scaling ScalingPolicy StepScalingPolicyConfiguration

Update requires: No interruption

TargetTrackingScalingPolicyConfiguration

Configures a target tracking scaling policy.

This parameter is required if you are creating a new policy and the policy type is TargetTrackingScaling.

Required: No

Type: Application Auto Scaling ScalingPolicy TargetTrackingScalingPolicyConfiguration

Update requires: No interruption

Return Value

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), such as 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

Application Auto Scaling Scaling Policy with a Step Policy Configuration

The following example creates an Application Auto Scaling scaling policy with a step policy configuration. When an associated alarm is triggered, the policy increases the desired count of the scalable target by 200%, with a cooldown period of 60 seconds.

JSON

"scalingPolicy" : {
  "Type" : "AWS::ApplicationAutoScaling::ScalingPolicy",
  "Properties" : {
    "PolicyName" : "AStepPolicy",
    "PolicyType" : "StepScaling",
    "ScalingTargetId" : {"Ref": "scalableTarget"},
    "StepScalingPolicyConfiguration" : {
      "AdjustmentType" : "PercentChangeInCapacity",
      "Cooldown" : 60,
      "MetricAggregationType" : "Average",
      "StepAdjustments" : [{
        "MetricIntervalLowerBound" : 0,
        "ScalingAdjustment" : 200
      }]
    }
  }
}

YAML

scalingPolicy:
  Type: 'AWS::ApplicationAutoScaling::ScalingPolicy'
  Properties:
    PolicyName: AStepPolicy
    PolicyType: StepScaling
    ScalingTargetId:
      Ref: scalableTarget
    StepScalingPolicyConfiguration:
      AdjustmentType: PercentChangeInCapacity
      Cooldown: 60
      MetricAggregationType: Average
      StepAdjustments:
      - MetricIntervalLowerBound: 0
        ScalingAdjustment: 200

Application Auto Scaling Scaling Policy with an Amazon DynamoDB Table

This example sets up Application Auto Scaling for a AWS::DynamoDB::Table resource. The template defines a TargetTrackingScaling scaling policy that scales up the WriteCapacityUnits throughput for the table.

JSON

{
  "Resources": {
    "DDBTable": {
      "Type": "AWS::DynamoDB::Table",
      "Properties": {
        "AttributeDefinitions": [
          {
            "AttributeName": "ArtistId",
            "AttributeType": "S"
          },
          {
            "AttributeName": "Concert",
            "AttributeType": "S"
          },
          {
            "AttributeName": "TicketSales",
            "AttributeType": "S"
          }
        ],
        "KeySchema": [
          {
            "AttributeName": "ArtistId",
            "KeyType": "HASH"
          },
          {
            "AttributeName": "Concert",
            "KeyType": "RANGE"
          }
        ],
        "GlobalSecondaryIndexes": [
          {
            "IndexName": "GSI",
            "KeySchema": [
              {
                "AttributeName": "TicketSales",
                "KeyType": "HASH"
              }
            ],
            "Projection": {
              "ProjectionType": "KEYS_ONLY"
            },
            "ProvisionedThroughput": {
              "ReadCapacityUnits": 5,
              "WriteCapacityUnits": 5
            }
          }
        ],
        "ProvisionedThroughput": {
          "ReadCapacityUnits": 5,
          "WriteCapacityUnits": 5
        }
      }
    },
    "WriteCapacityScalableTarget": {
      "Type": "AWS::ApplicationAutoScaling::ScalableTarget",
      "Properties": {
        "MaxCapacity": 15,
        "MinCapacity": 5,
        "ResourceId": { "Fn::Join": [
          "/",
          [
            "table",
            { "Ref": "DDBTable" }
          ]
        ] },
        "RoleARN": {
          "Fn::GetAtt": ["ScalingRole", "Arn"]
        },
        "ScalableDimension": "dynamodb:table:WriteCapacityUnits",
        "ServiceNamespace": "dynamodb"
      }
    },
    "ScalingRole": {
      "Type": "AWS::IAM::Role",
      "Properties": {
        "AssumeRolePolicyDocument": {
          "Version": "2012-10-17",
          "Statement": [
            {
              "Effect": "Allow",
              "Principal": {
                "Service": [
                  "application-autoscaling.amazonaws.com"
                ]
              },
              "Action": [
                "sts:AssumeRole"
              ]
            }
          ]
        },
        "Path": "/",
        "Policies": [
          {
            "PolicyName": "root",
            "PolicyDocument": {
              "Version": "2012-10-17",
              "Statement": [
                {
                  "Effect": "Allow",
                  "Action": [
                    "dynamodb:DescribeTable",
                    "dynamodb:UpdateTable",
                    "cloudwatch:PutMetricAlarm",
                    "cloudwatch:DescribeAlarms",
                    "cloudwatch:GetMetricStatistics",
                    "cloudwatch:SetAlarmState",
                    "cloudwatch:DeleteAlarms"
                  ],
                  "Resource": "*"
                }
              ]
            }
          }
        ]
      }
    },
    "WriteScalingPolicy": {
      "Type": "AWS::ApplicationAutoScaling::ScalingPolicy",
      "Properties": {
        "PolicyName": "WriteAutoScalingPolicy",
        "PolicyType": "TargetTrackingScaling",
        "ScalingTargetId": {
          "Ref": "WriteCapacityScalableTarget"
        },
        "TargetTrackingScalingPolicyConfiguration": {
          "TargetValue": 50.0,
          "ScaleInCooldown": 60,
          "ScaleOutCooldown": 60,
          "PredefinedMetricSpecification": {
            "PredefinedMetricType": "DynamoDBWriteCapacityUtilization"
          }
        }
      }
    }
  }
}

YAML

Resources:
  DDBTable:
    Type: "AWS::DynamoDB::Table"
    Properties:
      AttributeDefinitions:
        -
          AttributeName: "ArtistId"
          AttributeType: "S"
        -
          AttributeName: "Concert"
          AttributeType: "S"
        -
          AttributeName: "TicketSales"
          AttributeType: "S"
      KeySchema:
        -
          AttributeName: "ArtistId"
          KeyType: "HASH"
        -
          AttributeName: "Concert"
          KeyType: "RANGE"
      GlobalSecondaryIndexes:
        -
          IndexName: "GSI"
          KeySchema:
            -
              AttributeName: "TicketSales"
              KeyType: "HASH"
          Projection:
            ProjectionType: "KEYS_ONLY"
          ProvisionedThroughput:
            ReadCapacityUnits: 5
            WriteCapacityUnits: 5
      ProvisionedThroughput:
        ReadCapacityUnits: 5
        WriteCapacityUnits: 5
  WriteCapacityScalableTarget:
    Type: "AWS::ApplicationAutoScaling::ScalableTarget"
    Properties:
      MaxCapacity: 15
      MinCapacity: 5
      ResourceId: !Join
        - /
        - - table
          - !Ref DDBTable
      RoleARN: !GetAtt ScalingRole.Arn
      ScalableDimension: dynamodb:table:WriteCapacityUnits
      ServiceNamespace: dynamodb
  ScalingRole:
    Type: "AWS::IAM::Role"
    Properties:
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          -
            Effect: "Allow"
            Principal:
              Service:
                - application-autoscaling.amazonaws.com
            Action:
              - "sts:AssumeRole"
      Path: "/"
      Policies:
        -
          PolicyName: "root"
          PolicyDocument:
            Version: "2012-10-17"
            Statement:
              -
                Effect: "Allow"
                Action:
                  - "dynamodb:DescribeTable"
                  - "dynamodb:UpdateTable"
                  - "cloudwatch:PutMetricAlarm"
                  - "cloudwatch:DescribeAlarms"
                  - "cloudwatch:GetMetricStatistics"
                  - "cloudwatch:SetAlarmState"
                  - "cloudwatch:DeleteAlarms"
                Resource: "*"
  WriteScalingPolicy:
    Type: "AWS::ApplicationAutoScaling::ScalingPolicy"
    Properties:
      PolicyName: WriteAutoScalingPolicy
      PolicyType: TargetTrackingScaling
      ScalingTargetId: !Ref WriteCapacityScalableTarget
      TargetTrackingScalingPolicyConfiguration:
        TargetValue: 50.0
        ScaleInCooldown: 60
        ScaleOutCooldown: 60
        PredefinedMetricSpecification:
          PredefinedMetricType: DynamoDBWriteCapacityUtilization