Setting up an Application Load Balancer to 2 Tomcats on EC2

Question

Good morning, I have 2 Tomcats running on an EC2 (Windows Server 2022). They are serving requests on the Private IP of the EC2 via ports 8080 and 8081 and I can get to both the Healthy Target URL and App from the EC2 instance itself. I have 2 Target groups created. One accepts HTTP inbound and the other accepts HTTPS inbound. The Healthy Target check is sent to <EC2 Host><8080> and <8081> (index.jsp) via HTTP for both LBs The app resides at <EC2 Host><8080>/myapp/index and <8081> <EC2 Host><8081>/myapp/index

I try to create a Load Balancer (listening on port 80) and when I try to select a Target, the list is empty and refresh doesn't populate the list. What am I missing? Does the subnet of the target group have anything to do with it? please advise. thanks Charlie D

Kallu · Accepted Answer

Are you creating a new load balancer (ALB) and trying to configure it to the same target group that is already used for another ALB?
If this is the case, you need to create a new target group (you can use the same targets as in other groups) 
> You can specify the same target group in multiple listeners, but these listeners must belong to the same Application Load Balancer. 
See https://docs.aws.amazon.com/elasticloadbalancing/latest/application/create-target-group.html

Setting up an Application Load Balancer to 2 Tomcats on EC2

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