AWS Error : None of these Availability Zones contains a healthy target. Requests are being routed to all targets. in AWS

Question

I have created a Application Load Balance in Aws. I have created 2 EC2 and make them a group. After that I add that group to the ALB with listener 80.

But when the syste

Answer 1

I was running into this issue, and also getting a 504 Gateway timeout, and it ended up being this missing rule from the documentation.

1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2. In the left navigation, choose Security Groups.

3. Choose the security group that your container instances use. If you created your container instances by using the Amazon ECS first run wizard, this security group may have the description, ECS Allowed Ports.

4. Choose the Inbound tab, and then choose Edit.

5. For Type, choose All traffic.

6. For Source, choose Custom, and then type the name of your Application Load Balancer security group that you created in Configure Security Groups. This rule allows all traffic from your Application Load Balancer to reach the containers in your tasks that are registered with your load balancer.

7. Choose Save to finish.