class aws_cdk.aws_ecs_patterns.QueueProcessingServiceBase(scope, id, *, capacity_provider_strategies=None, circuit_breaker=None, cluster=None, command=None, cooldown=None, cpu_target_utilization_percent=None, deployment_controller=None, disable_cpu_based_scaling=None, enable_ecs_managed_tags=None, enable_execute_command=None, enable_logging=None, environment=None, family=None, image=None, log_driver=None, max_healthy_percent=None, max_receive_count=None, max_scaling_capacity=None, min_healthy_percent=None, min_scaling_capacity=None, propagate_tags=None, queue=None, retention_period=None, scaling_steps=None, secrets=None, service_name=None, visibility_timeout=None, vpc=None)

Bases: Construct

The base class for QueueProcessingEc2Service and QueueProcessingFargateService services.

Constructs a new instance of the QueueProcessingServiceBase class.

  • scope (Construct) –

  • id (str) –

  • capacity_provider_strategies (Optional[Sequence[Union[CapacityProviderStrategy, Dict[str, Any]]]]) – A list of Capacity Provider strategies used to place a service. Default: - undefined

  • circuit_breaker (Union[DeploymentCircuitBreaker, Dict[str, Any], None]) – Whether to enable the deployment circuit breaker. If this property is defined, circuit breaker will be implicitly enabled. Default: - disabled

  • cluster (Optional[ICluster]) – The name of the cluster that hosts the service. If a cluster is specified, the vpc construct should be omitted. Alternatively, you can omit both cluster and vpc. Default: - create a new cluster; if both cluster and vpc are omitted, a new VPC will be created for you.

  • command (Optional[Sequence[str]]) – The command that is passed to the container. If you provide a shell command as a single string, you have to quote command-line arguments. Default: - CMD value built into container image.

  • cooldown (Optional[Duration]) – Grace period after scaling activity in seconds. Subsequent scale outs during the cooldown period are squashed so that only the biggest scale out happens. Subsequent scale ins during the cooldown period are ignored. Default: 300 seconds

  • cpu_target_utilization_percent (Union[int, float, None]) – The target CPU utilization percentage for CPU based scaling strategy when enabled. Default: - 50

  • deployment_controller (Union[DeploymentController, Dict[str, Any], None]) – Specifies which deployment controller to use for the service. For more information, see Amazon ECS Deployment Types Default: - Rolling update (ECS)

  • disable_cpu_based_scaling (Optional[bool]) – Flag to disable CPU based auto scaling strategy on the service. Default: - false

  • enable_ecs_managed_tags (Optional[bool]) – Specifies whether to enable Amazon ECS managed tags for the tasks within the service. For more information, see Tagging Your Amazon ECS Resources Default: false

  • enable_execute_command (Optional[bool]) – Whether ECS Exec should be enabled. Default: - false

  • enable_logging (Optional[bool]) – Flag to indicate whether to enable logging. Default: true

  • environment (Optional[Mapping[str, str]]) – The environment variables to pass to the container. The variable QUEUE_NAME with value queue.queueName will always be passed. Default: ‘QUEUE_NAME: queue.queueName’

  • family (Optional[str]) – The name of a family that the task definition is registered to. A family groups multiple versions of a task definition. Default: - Automatically generated name.

  • image (Optional[ContainerImage]) – The image used to start a container. For QueueProcessingFargateService, either image or taskDefinition must be specified, but not both. For QueueProcessingEc2Service, image is required. Default: - the image of the task definition is used for Fargate, required otherwise

  • log_driver (Optional[LogDriver]) – The log driver to use. Default: - AwsLogDriver if enableLogging is true

  • max_healthy_percent (Union[int, float, None]) – The maximum number of tasks, specified as a percentage of the Amazon ECS service’s DesiredCount value, that can run in a service during a deployment. Default: - default from underlying service.

  • max_receive_count (Union[int, float, None]) – The maximum number of times that a message can be received by consumers. When this value is exceeded for a message the message will be automatically sent to the Dead Letter Queue. If the queue construct is specified, maxReceiveCount should be omitted. Default: 3

  • max_scaling_capacity (Union[int, float, None]) – Maximum capacity to scale to. Default: 2

  • min_healthy_percent (Union[int, float, None]) – The minimum number of tasks, specified as a percentage of the Amazon ECS service’s DesiredCount value, that must continue to run and remain healthy during a deployment. Default: - default from underlying service.

  • min_scaling_capacity (Union[int, float, None]) – Minimum capacity to scale to. Default: 1

  • propagate_tags (Optional[PropagatedTagSource]) – Specifies whether to propagate the tags from the task definition or the service to the tasks in the service. Tags can only be propagated to the tasks within the service during service creation. Default: - none

  • queue (Optional[IQueue]) – A queue for which to process items from. If specified and this is a FIFO queue, the queue name must end in the string ‘.fifo’. See CreateQueue Default: ‘SQSQueue with CloudFormation-generated name’

  • retention_period (Optional[Duration]) – The number of seconds that Dead Letter Queue retains a message. If the queue construct is specified, retentionPeriod should be omitted. Default: Duration.days(14)

  • scaling_steps (Optional[Sequence[Union[ScalingInterval, Dict[str, Any]]]]) – The intervals for scaling based on the SQS queue’s ApproximateNumberOfMessagesVisible metric. Maps a range of metric values to a particular scaling behavior. See Simple and Step Scaling Policies for Amazon EC2 Auto Scaling Default: [{ upper: 0, change: -1 },{ lower: 100, change: +1 },{ lower: 500, change: +5 }]

  • secrets (Optional[Mapping[str, Secret]]) – The secret to expose to the container as an environment variable. Default: - No secret environment variables.

  • service_name (Optional[str]) – The name of the service. Default: - CloudFormation-generated name.

  • visibility_timeout (Optional[Duration]) – Timeout of processing a single message. After dequeuing, the processor has this much time to handle the message and delete it from the queue before it becomes visible again for dequeueing by another processor. Values must be between 0 and (12 hours). If the queue construct is specified, visibilityTimeout should be omitted. Default: Duration.seconds(30)

  • vpc (Optional[IVpc]) – The VPC where the container instances will be launched or the elastic network interfaces (ENIs) will be deployed. If a vpc is specified, the cluster construct should be omitted. Alternatively, you can omit both vpc and cluster. Default: - uses the VPC defined in the cluster or creates a new VPC.



Returns a string representation of this construct.

Return type:




The cluster where your service will be deployed.


The dead letter queue for the primary SQS queue.


Environment variables that will include the queue name.


The AwsLogDriver to use for logging if logging is enabled.


The maximum number of instances for autoscaling to scale up to.


The minimum number of instances for autoscaling to scale down to.


The tree node.


The scaling interval for autoscaling based off an SQS Queue size.


The secret environment variables.


The SQS queue that the service will process from.

Static Methods

classmethod is_construct(x)

Checks if x is a construct.

Use this method instead of instanceof to properly detect Construct instances, even when the construct library is symlinked.

Explanation: in JavaScript, multiple copies of the constructs library on disk are seen as independent, completely different libraries. As a consequence, the class Construct in each copy of the constructs library is seen as a different class, and an instance of one class will not test as instanceof the other class. npm install will not create installations like this, but users may manually symlink construct libraries together or use a monorepo tool: in those cases, multiple copies of the constructs library can be accidentally installed, and instanceof will behave unpredictably. It is safest to avoid using instanceof, and using this type-testing method instead.


x (Any) – Any object.

Return type:



true if x is an object created from a class which extends Construct.