While some Docker containers accept TCP client requests, other Docker containers accept client requests on an HTTP path. As demonstrated in Chapter 2, Networking, an HTTP request to a Hello World application task could be made on the public IP address exposed by the Hello World task. An ECS service includes built-in internal load balancing to distribute client traffic between the tasks in a service.

Problem : Each task in an ECS service with Fargate launch is associated with an ENI and a public IP. When an application is scaled up to run multiple tasks, multiple ENIs are created, and each task must be accessed on its public IP address.

Although internal load balancing is provided, no provision is included to balance client traffic externally between the different tasks' IP addresses. A single task could receive an inordinate number of client requests, while another task could receive relatively fewer client requests, or even none, which would result...