What is the protocol of the target group be for an Application Load Balancer and how to register targets

Question

The create service for the ECS console does not work. So what I am doing is creating all the security groups, load balancers, and target groups that I needed before hand and then creating the service. I create
* Security group A that allows https traffic port 443 from the remote client to the Application Load balancer  
* Security group B that allows http port 8080 traffic from the Application Load balancer to the server in the task container
* Application Load balancer (ALB) using
  * security group A
  * listener using https on port 443
  * target group T

So the target group for the ALB has a protocol and a health check protocol. The health check protocol I assume must be set to http port 8080 since that is what the service in the container needs. But I do not know what the protocol is. The default shows https:443 perhaps because the listener on the ALB (this target group was created from the EC3 load balancer creator) was https:443. I do not know what this protocol is referring to.

Now the registration page has one specify an IP address and 'include as pending below'.

Can I pick any ip address that is supported by my VPC such as 10.0.0.16?
I do not know what the 'include as pending below' means. Note that I have not created the service yet, but just am trying to setup the items needed in the service.

Answer

In the context of an Application Load Balancer (ALB), the protocol of the target group defines the protocol that the load balancer uses to communicate with the registered targets. This will typically be HTTP but sometimes it is HTTPS depending on the use-case.

The health check protocol is what the load balancer uses to check the health of its registered targets. This can be either HTTP or HTTPS, and it determines how to route traffic based on the results of the health checks.

For your situation, you could set both the target group's protocol and the health check protocol to HTTP. The ALB will receive traffic on HTTPS (due to the listener setup) and forward it to the targets using HTTP, which will be received on port 8080.

When it comes to registering targets, if you're working with Amazon ECS services, you don't manually specify an IP address. Instead, you associate the target group with the ECS service during the service creation. Amazon ECS will automatically register and deregister container instances with the load balancer.

In your case, you do not need to manually register any targets to the target group at this point. When you create the ECS service, you will specify this target group, and Amazon ECS will automatically register the tasks in your service with the target group using the IP of the ENI (Elastic Network Interface) that is attached to the task.

"Include as pending below" refers to targets that have not yet passed initial health checks. They are in the "initial" state and are not yet considered healthy or unhealthy. Remember to set the appropriate security groups for your ECS service to allow incoming traffic from the ALB to your ECS tasks.

So, once your target group, listener, and ALB are set up, you can proceed to create the ECS service and specify the target group in the service definition. Once the service is running and tasks are launched, they should be registered to the target group automatically, and you should be able to see incoming traffic being routed correctly.

What is the protocol of the target group be for an Application Load Balancer and how to register targets

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