For more information, see Service Load Balancing in the value of 200%, the scheduler can start four new tasks before stopping the four older tasks (provided that the cluster resources required to do this are available).The default value for a replica service for The name of your service.Currently, you are limited to one load balancer or target group per service.
This parameter is only permitted if you are using a load balancer with your service and your task definition does not use the Warning If your account has already created the Amazon ECS service-linked role, that role is used by default for your service unless you specify a role here.
Services with tasks that use the network mode (for example, those with the Fargate launch type) only support Application Load Balancers and Network Load Balancers; Classic Load Balancers are not supported.
Also, when you create any target groups for these services, you must choose network mode (for example, those with the Fargate launch type) only support Application Load Balancers and Network Load Balancers; Classic Load Balancers are not supported.
You can also update the deployment configuration of a service.
When a deployment is triggered by updating the task definition of a service, the service scheduler uses the deployment configuration parameters, Note Updating a service to add a subnet to a list of existing subnets does not trigger a service deployment. You can use this option to trigger a new deployment with no service definition changes.