Menu
Application Auto Scaling
API Reference (API Version 2016-02-06)

DescribeScalingPolicies

Provides descriptive information about the scaling policies in the specified namespace.

You can filter the results using the ResourceId, ScalableDimension, and PolicyNames parameters.

To create a scaling policy or update an existing one, see PutScalingPolicy. If you are no longer using a scaling policy, you can delete it using DeleteScalingPolicy.

Request Syntax

{
   "MaxResults": number,
   "NextToken": "string",
   "PolicyNames": [ "string" ],
   "ResourceId": "string",
   "ScalableDimension": "string",
   "ServiceNamespace": "string"
}

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.

MaxResults

The maximum number of scalable target results. This value can be between 1 and 50. The default value is 50.

If this parameter is used, the operation returns up to MaxResults results at a time, along with a NextToken value. To get the next set of results, include the NextToken value in a subsequent call. If this parameter is not used, the operation returns up to 50 results and a NextToken value, if applicable.

Type: Integer

Required: No

NextToken

The token for the next set of results.

Type: String

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

Required: No

PolicyNames

The names of the scaling policies to describe.

Type: Array of strings

Length Constraints: Minimum length of 1. Maximum length of 1600.

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

Required: No

ResourceId

The identifier of the resource associated with the scaling policy. This string consists of the resource type and unique identifier. If you specify a scalable dimension, you must also specify a resource ID.

  • 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 resource ID. Example: table/my-table.

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

Type: String

Length Constraints: Minimum length of 1. Maximum length of 1600.

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

Required: No

ScalableDimension

The scalable dimension. This string consists of the service namespace, resource type, and scaling property. If you specify a scalable dimension, you must also specify a resource ID.

  • 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.

Type: String

Valid Values: ecs:service:DesiredCount | ec2:spot-fleet-request:TargetCapacity | elasticmapreduce:instancegroup:InstanceCount | appstream:fleet:DesiredCapacity | dynamodb:table:ReadCapacityUnits | dynamodb:table:WriteCapacityUnits | dynamodb:index:ReadCapacityUnits | dynamodb:index:WriteCapacityUnits

Required: No

ServiceNamespace

The namespace of the AWS service. For more information, see AWS Service Namespaces in the Amazon Web Services General Reference.

Type: String

Valid Values: ecs | elasticmapreduce | ec2 | appstream | dynamodb

Required: Yes

Response Syntax

{
   "NextToken": "string",
   "ScalingPolicies": [ 
      { 
         "Alarms": [ 
            { 
               "AlarmARN": "string",
               "AlarmName": "string"
            }
         ],
         "CreationTime": number,
         "PolicyARN": "string",
         "PolicyName": "string",
         "PolicyType": "string",
         "ResourceId": "string",
         "ScalableDimension": "string",
         "ServiceNamespace": "string",
         "StepScalingPolicyConfiguration": { 
            "AdjustmentType": "string",
            "Cooldown": number,
            "MetricAggregationType": "string",
            "MinAdjustmentMagnitude": number,
            "StepAdjustments": [ 
               { 
                  "MetricIntervalLowerBound": number,
                  "MetricIntervalUpperBound": number,
                  "ScalingAdjustment": number
               }
            ]
         },
         "TargetTrackingScalingPolicyConfiguration": { 
            "CustomizedMetricSpecification": { 
               "Dimensions": [ 
                  { 
                     "Name": "string",
                     "Value": "string"
                  }
               ],
               "MetricName": "string",
               "Namespace": "string",
               "Statistic": "string",
               "Unit": "string"
            },
            "DisableScaleIn": boolean,
            "PredefinedMetricSpecification": { 
               "PredefinedMetricType": "string",
               "ResourceLabel": "string"
            },
            "ScaleInCooldown": number,
            "ScaleOutCooldown": number,
            "TargetValue": number
         }
      }
   ]
}

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

NextToken

The token required to get the next set of results. This value is null if there are no more results to return.

Type: String

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

ScalingPolicies

A list of scaling policy objects.

Type: Array of ScalingPolicy objects

Errors

For information about the errors that are common to all actions, see Common Errors.

ConcurrentUpdateException

Concurrent updates caused an exception, for example, if you request an update to an Application Auto Scaling resource that already has a pending update.

HTTP Status Code: 400

FailedResourceAccessException

Failed access to resources caused an exception. This exception is thrown when Application Auto Scaling is unable to retrieve the alarms associated with a scaling policy due to a client error, for example, if the role ARN specified for a scalable target does not have permission to call the CloudWatch DescribeAlarms API operation on behalf of your account.

HTTP Status Code: 400

InternalServiceException

The service encountered an internal error.

HTTP Status Code: 400

InvalidNextTokenException

The next token supplied was invalid.

HTTP Status Code: 400

ValidationException

An exception was thrown for a validation issue. Review the available parameters for the API request.

HTTP Status Code: 400

Example

If you plan to create requests manually, you must replace the Authorization header contents in the examples (AUTHPARAMS) with a signature. For more information, see Signature Version 4 Signing Process in the AWS Gerneral Reference. If you plan to use the AWS CLI or one of the AWS SDKs, these tools sign the requests for you.

Example

The following example describes the scaling policies for the ecs service namespace.

Sample Request

POST / HTTP/1.1
Host: autoscaling.us-west-2.amazonaws.com
Accept-Encoding: identity
Content-Length: 27
X-Amz-Target: AnyScaleFrontendService.DescribeScalingPolicies
X-Amz-Date: 20160506T194435Z
User-Agent: aws-cli/1.10.23 Python/2.7.11 Darwin/15.4.0 botocore/1.4.8
Content-Type: application/x-amz-json-1.1
Authorization: AUTHPARAMS

{
    "ServiceNamespace": "ecs"
}

Sample Response

HTTP/1.1 200 OK
x-amzn-RequestId: f662c515-13c2-11e6-add4-41b78770ca43
Content-Type: application/x-amz-json-1.1
Content-Length: 1363
Date: Fri, 06 May 2016 19:44:35 GMT

{
    "ScalingPolicies": [
        {
            "Alarms": [
                {
                    "AlarmARN": "arn:aws:cloudwatch:us-west-2:012345678910:alarm:web-app-cpu-gt-75",
                    "AlarmName": "web-app-cpu-gt-75"
                }
            ],
            "CreationTime": 1462561899.23,
            "PolicyARN": "arn:aws:autoscaling:us-west-2:012345678910:scalingPolicy:6d8972f3-efc8-437c-92d1-6270f29a66e7:resource/ecs/service/default/web-app:policyName/web-app-cpu-gt-75",
            "PolicyName": "web-app-cpu-gt-75",
            "PolicyType": "StepScaling",
            "ResourceId": "service/default/web-app",
            "ScalableDimension": "ecs:service:DesiredCount",
            "ServiceNamespace": "ecs",
            "StepScalingPolicyConfiguration": {
                "AdjustmentType": "PercentChangeInCapacity",
                "Cooldown": 60,
                "StepAdjustments": [
                    {
                        "MetricIntervalLowerBound": 0,
                        "ScalingAdjustment": 200
                    }
                ]
            }
        },
        {
            "Alarms": [
                {
                    "AlarmARN": "arn:aws:cloudwatch:us-west-2:012345678910:alarm:web-app-cpu-lt-25",
                    "AlarmName": "web-app-cpu-lt-25"
                }
            ],
            "CreationTime": 1462562575.099,
            "PolicyARN": "arn:aws:autoscaling:us-west-2:012345678910:scalingPolicy:6d8972f3-efc8-437c-92d1-6270f29a66e7:resource/ecs/service/default/web-app:policyName/web-app-cpu-lt-25",
            "PolicyName": "web-app-cpu-lt-25",
            "PolicyType": "StepScaling",
            "ResourceId": "service/default/web-app",
            "ScalableDimension": "ecs:service:DesiredCount",
            "ServiceNamespace": "ecs",
            "StepScalingPolicyConfiguration": {
                "AdjustmentType": "PercentChangeInCapacity",
                "Cooldown": 1,
                "StepAdjustments": [
                    {
                        "MetricIntervalUpperBound": 0,
                        "ScalingAdjustment": -50
                    }
                ]
            }
        }
    ]
}

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: