AWS::ECS::Service DeploymentConfiguration

The DeploymentConfiguration property specifies optional deployment parameters that control how many tasks run during the deployment and the ordering of stopping and starting tasks.

Syntax

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

JSON

{
  "DeploymentCircuitBreaker" : DeploymentCircuitBreaker,
  "MaximumPercent" : Integer,
  "MinimumHealthyPercent" : Integer
}

YAML

  DeploymentCircuitBreaker: 
    DeploymentCircuitBreaker
  MaximumPercent: Integer
  MinimumHealthyPercent: Integer

Properties

DeploymentCircuitBreaker

Note

The deployment circuit breaker can only be used for services using the rolling update (ECS) deployment type that are not behind a Classic Load Balancer.

The deployment circuit breaker determines whether a service deployment will fail if the service can't reach a steady state. If enabled, a service deployment will transition to a failed state and stop launching new tasks. You can also enable Amazon ECS to roll back your service to the last completed deployment after a failure. For more information, see Rolling update in the Amazon Elastic Container Service Developer Guide.

Required: No

Type: DeploymentCircuitBreaker

Update requires: No interruption

MaximumPercent

If a service is using the rolling update (ECS) deployment type, the maximumPercent parameter represents an upper limit on the number of your service's tasks that are allowed in the RUNNING or PENDING state during a deployment, as a percentage of the desiredCount (rounded down to the nearest integer). This parameter enables you to define the deployment batch size. For example, if your service is using the REPLICA service scheduler and has a desiredCount of four tasks and a maximumPercent value of 200%, the scheduler may start four new tasks before stopping the four older tasks (provided that the cluster resources required to do this are available). The default maximumPercent value for a service using the REPLICA service scheduler is 200%.

If a service is using either the blue/green (CODE_DEPLOY) or EXTERNAL deployment types and tasks that use the EC2 launch type, the maximum percent value is set to the default value and is used to define the upper limit on the number of the tasks in the service that remain in the RUNNING state while the container instances are in the DRAINING state. If the tasks in the service use the Fargate launch type, the maximum percent value is not used, although it is returned when describing your service.

Required: No

Type: Integer

Update requires: No interruption

MinimumHealthyPercent

If a service is using the rolling update (ECS) deployment type, the minimumHealthyPercent represents a lower limit on the number of your service's tasks that must remain in the RUNNING state during a deployment, as a percentage of the desiredCount (rounded up to the nearest integer). This parameter enables you to deploy without using additional cluster capacity. For example, if your service has a desiredCount of four tasks and a minimumHealthyPercent of 50%, the service scheduler may stop two existing tasks to free up cluster capacity before starting two new tasks.

For services that do not use a load balancer, the following should be noted:

• A service is considered healthy if all essential containers within the tasks in the service pass their health checks.

• If a task has no essential containers with a health check defined, the service scheduler will wait for 40 seconds after a task reaches a RUNNING state before the task is counted towards the minimum healthy percent total.

• If a task has one or more essential containers with a health check defined, the service scheduler will wait for the task to reach a healthy status before counting it towards the minimum healthy percent total. A task is considered healthy when all essential containers within the task have passed their health checks. The amount of time the service scheduler can wait for is determined by the container health check settings.

For services are that do use a load balancer, the following should be noted:

• If a task has no essential containers with a health check defined, the service scheduler will wait for the load balancer target group health check to return a healthy status before counting the task towards the minimum healthy percent total.

• If a task has an essential container with a health check defined, the service scheduler will wait for both the task to reach a healthy status and the load balancer target group health check to return a healthy status before counting the task towards the minimum healthy percent total.

If a service is using either the blue/green (CODE_DEPLOY) or EXTERNAL deployment types and is running tasks that use the EC2 launch type, the minimum healthy percent value is set to the default value and is used to define the lower limit on the number of the tasks in the service that remain in the RUNNING state while the container instances are in the DRAINING state. If a service is using either the blue/green (CODE_DEPLOY) or EXTERNAL deployment types and is running tasks that use the Fargate launch type, the minimum healthy percent value is not used, although it is returned when describing your service.

Required: No

Type: Integer

Update requires: No interruption