AWS::ECS::Service CapacityProviderStrategyItem - Amazon CloudFormation
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AWS::ECS::Service CapacityProviderStrategyItem

The details of a capacity provider strategy. A capacity provider strategy can be set when using the RunTask or CreateService APIs or as the default capacity provider strategy for a cluster with the CreateCluster API.

Only capacity providers that are already associated with a cluster and have an ACTIVE or UPDATING status can be used in a capacity provider strategy. The PutClusterCapacityProviders API is used to associate a capacity provider with a cluster.

If specifying a capacity provider that uses an Auto Scaling group, the capacity provider must already be created. New Auto Scaling group capacity providers can be created with the CreateCapacityProvider API operation.

To use an Amazon Fargate capacity provider, specify either the FARGATE or FARGATE_SPOT capacity providers. The Amazon Fargate capacity providers are available to all accounts and only need to be associated with a cluster to be used in a capacity provider strategy.


To declare this entity in your Amazon CloudFormation template, use the following syntax:


{ "Base" : Integer, "CapacityProvider" : String, "Weight" : Integer }


Base: Integer CapacityProvider: String Weight: Integer



The base value designates how many tasks, at a minimum, to run on the specified capacity provider. Only one capacity provider in a capacity provider strategy can have a base defined. If no value is specified, the default value of 0 is used.

Required: No

Type: Integer

Minimum: 0

Maximum: 100000

Update requires: No interruption


The short name of the capacity provider.

Required: No

Type: String

Update requires: No interruption


The weight value designates the relative percentage of the total number of tasks launched that should use the specified capacity provider. The weight value is taken into consideration after the base value, if defined, is satisfied.

If no weight value is specified, the default value of 0 is used. When multiple capacity providers are specified within a capacity provider strategy, at least one of the capacity providers must have a weight value greater than zero and any capacity providers with a weight of 0 can't be used to place tasks. If you specify multiple capacity providers in a strategy that all have a weight of 0, any RunTask or CreateService actions using the capacity provider strategy will fail.

An example scenario for using weights is defining a strategy that contains two capacity providers and both have a weight of 1, then when the base is satisfied, the tasks will be split evenly across the two capacity providers. Using that same logic, if you specify a weight of 1 for capacityProviderA and a weight of 4 for capacityProviderB, then for every one task that's run using capacityProviderA, four tasks would use capacityProviderB.

Required: No

Type: Integer

Minimum: 0

Maximum: 1000

Update requires: No interruption