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

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RegisterScalableTarget

Registers or updates a scalable target. A scalable target is a resource that Application Auto Scaling can scale out and scale in. Scalable targets are uniquely identified by the combination of resource ID, scalable dimension, and namespace.

When you register a new scalable target, you must specify values for minimum and maximum capacity. Application Auto Scaling will not scale capacity to values that are outside of this range.

To update a scalable target, specify the parameter that you want to change as well as the following parameters that identify the scalable target: resource ID, scalable dimension, and namespace. Any parameters that you don't specify are not changed by this update request.

After you register a scalable target, you do not need to register it again to use other Application Auto Scaling operations. To see which resources have been registered, use DescribeScalableTargets. You can also view the scaling policies for a service namespace by using DescribeScalableTargets.

If you no longer need a scalable target, you can deregister it by using DeregisterScalableTarget.

Request Syntax

{ "MaxCapacity": number, "MinCapacity": number, "ResourceId": "string", "RoleARN": "string", "ScalableDimension": "string", "ServiceNamespace": "string", "SuspendedState": { "DynamicScalingInSuspended": boolean, "DynamicScalingOutSuspended": boolean, "ScheduledScalingSuspended": boolean } }

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.

MaxCapacity

The maximum value to scale to in response to a scale-out event. MaxCapacity is required to register a scalable target.

Type: Integer

Required: No

MinCapacity

The minimum value to scale to in response to a scale-in event. MinCapacity is required to register a scalable target.

Type: Integer

Required: No

ResourceId

The identifier of the resource that is associated with the scalable target. 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 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.

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

  • Amazon SageMaker endpoint variants - 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.

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: Yes

RoleARN

Application Auto Scaling creates a service-linked role that grants it permissions to modify the scalable target on your behalf. For more information, see Service-Linked Roles for Application Auto Scaling.

For resources that are not supported using a service-linked role, this parameter is required, and it must specify the ARN of an IAM role that allows Application Auto Scaling to modify the scalable target on your behalf.

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 associated with the scalable target. 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.

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 | rds:cluster:ReadReplicaCount | sagemaker:variant:DesiredInstanceCount | custom-resource:ResourceType:Property

Required: Yes

ServiceNamespace

The namespace of the AWS service that provides the resource or custom-resource for a resource provided by your own application or service. For more information, see AWS Service Namespaces in the Amazon Web Services General Reference.

Type: String

Valid Values: ecs | elasticmapreduce | ec2 | appstream | dynamodb | rds | sagemaker | custom-resource

Required: Yes

SuspendedState

An embedded object that contains attributes and attribute values that are used to suspend and resume automatic scaling. Setting the value of an attribute to true suspends the specified scaling activities. Setting it to false (default) resumes the specified scaling activities.

Suspension Outcomes

  • For DynamicScalingInSuspended, while a suspension is in effect, all scale-in activities that are triggered by a scaling policy are suspended.

  • For DynamicScalingOutSuspended, while a suspension is in effect, all scale-out activities that are triggered by a scaling policy are suspended.

  • For ScheduledScalingSuspended, while a suspension is in effect, all scaling activities that involve scheduled actions are suspended.

For more information, see Suspend and Resume Application Auto Scaling in the Application Auto Scaling User Guide.

Type: SuspendedState object

Required: No

Response Elements

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

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

InternalServiceException

The service encountered an internal error.

HTTP Status Code: 400

LimitExceededException

A per-account resource limit is exceeded. For more information, see Application Auto Scaling Limits.

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 Amazon Web Services General 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 registers an Amazon ECS service with Application Auto Scaling.

Sample Request

POST / HTTP/1.1 Host: autoscaling.us-west-2.amazonaws.com Accept-Encoding: identity Content-Length: 229 X-Amz-Target: AnyScaleFrontendService.RegisterScalableTarget X-Amz-Date: 20160506T182145Z 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 { "ScalableDimension": "ecs:service:DesiredCount", "ResourceId": "service/default/web-app", "RoleARN": "arn:aws:iam::012345678910:role/ApplicationAutoscalingECSRole", "MinCapacity": 1, "ServiceNamespace": "ecs", "MaxCapacity": 10 }

See Also

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