Cluster - Amazon Elastic Container Service


A regional grouping of one or more container instances on which you can run task requests. Each account receives a default cluster the first time you use the Amazon ECS service, but you may also create other clusters. Clusters may contain more than one instance type simultaneously.



The number of services that are running on the cluster in an ACTIVE state. You can view these services with ListServices.

Type: Integer

Required: No


The resources attached to a cluster. When using a capacity provider with a cluster, the Auto Scaling plan that is created will be returned as a cluster attachment.

Type: Array of Attachment objects

Required: No


The status of the capacity providers associated with the cluster. The following are the states that will be returned:


The available capacity providers for the cluster are updating. This occurs when the Auto Scaling plan is provisioning or deprovisioning.


The capacity providers have successfully updated.


The capacity provider updates failed.

Type: String

Required: No


The capacity providers associated with the cluster.

Type: Array of strings

Required: No


The Amazon Resource Name (ARN) that identifies the cluster. The ARN contains the arn:aws:ecs namespace, followed by the Region of the cluster, the AWS account ID of the cluster owner, the cluster namespace, and then the cluster name. For example, arn:aws:ecs:region:012345678910:cluster/test.

Type: String

Required: No


A user-generated string that you use to identify your cluster.

Type: String

Required: No


The default capacity provider strategy for the cluster. When services or tasks are run in the cluster with no launch type or capacity provider strategy specified, the default capacity provider strategy is used.

Type: Array of CapacityProviderStrategyItem objects

Required: No


The number of tasks in the cluster that are in the PENDING state.

Type: Integer

Required: No


The number of container instances registered into the cluster. This includes container instances in both ACTIVE and DRAINING status.

Type: Integer

Required: No


The number of tasks in the cluster that are in the RUNNING state.

Type: Integer

Required: No


The settings for the cluster. This parameter indicates whether CloudWatch Container Insights is enabled or disabled for a cluster.

Type: Array of ClusterSetting objects

Required: No


Additional information about your clusters that are separated by launch type, including:

  • runningEC2TasksCount

  • RunningFargateTasksCount

  • pendingEC2TasksCount

  • pendingFargateTasksCount

  • activeEC2ServiceCount

  • activeFargateServiceCount

  • drainingEC2ServiceCount

  • drainingFargateServiceCount

Type: Array of KeyValuePair objects

Required: No


The status of the cluster. The following are the possible states that will be returned.


The cluster is ready to accept tasks and if applicable you can register container instances with the cluster.


The cluster has capacity providers associated with it and the resources needed for the capacity provider are being created.


The cluster has capacity providers associated with it and the resources needed for the capacity provider are being deleted.


The cluster has capacity providers associated with it and the resources needed for the capacity provider have failed to create.


The cluster has been deleted. Clusters with an INACTIVE status may remain discoverable in your account for a period of time. However, this behavior is subject to change in the future, so you should not rely on INACTIVE clusters persisting.

Type: String

Required: No


The metadata that you apply to the cluster to help you categorize and organize them. Each tag consists of a key and an optional value, both of which you define.

The following basic restrictions apply to tags:

  • Maximum number of tags per resource - 50

  • For each resource, each tag key must be unique, and each tag key can have only one value.

  • Maximum key length - 128 Unicode characters in UTF-8

  • Maximum value length - 256 Unicode characters in UTF-8

  • If your tagging schema is used across multiple services and resources, remember that other services may have restrictions on allowed characters. Generally allowed characters are: letters, numbers, and spaces representable in UTF-8, and the following characters: + - = . _ : / @.

  • Tag keys and values are case-sensitive.

  • Do not use aws:, AWS:, or any upper or lowercase combination of such as a prefix for either keys or values as it is reserved for AWS use. You cannot edit or delete tag keys or values with this prefix. Tags with this prefix do not count against your tags per resource limit.

Type: Array of Tag objects

Array Members: Minimum number of 0 items. Maximum number of 50 items.

Required: No

See Also

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