Service
Optional deployment parameters that control how many tasks run during a deployment and the ordering of stopping and starting tasks.
Constructors
Properties
Information about the CloudWatch alarms.
The deployment circuit breaker can only be used for services using the rolling update (`ECS`) deployment type. The deployment circuit breaker determines whether a service deployment will fail if the service can't reach a steady state. If you use the deployment circuit breaker, a service deployment will transition to a failed state and stop launching new tasks. If you use the rollback option, when a service deployment fails, the service is rolled back to the last deployment that completed successfully. For more information, see Rolling update in the Amazon Elastic Container Service Developer Guide
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 in the service use the EC2 launch type, the maximum percent value is set to the default value. The maximum percent value 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. You can't specify a custom `maximumPercent` value for a service that uses either the blue/green (`CODE_DEPLOY`) or `EXTERNAL` deployment types and has tasks that use the EC2 launch type. 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.
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: