Target health check failing continuously

Question

For a new instance created for EC2 in AWS cloud, trying to assign the same to load balancer based on target group.

Steps followed:

• Created load balancer
• Created EC2 instance and configured security group with inbound traffic allowed from load balancer
• Created target group and added EC2 instance in target
• Configured the listener in load balancer to redirect specific path ('/taskA/*') to newly created target group.

After above steps waited for a while for target groups to initialize and setup. Later observed that under Registered targets section, status shows unhealthy and it says health check failed.

Not sure what needs to be checked since the status description also dont mention exact failure reasons.

Please help to understand better this issue by sharing your views.

Expecting the target group to work as expected and for any incoming request it should check for url path configured and redirect to specific instance page as configured in load balancer.

Answer 1

Target group health check is different from instance health check.

Its purpose is to check if the application in your instance works correctly by sending request to the port which you specified and check if that port returns http status code as expected.

There must be application running on your selected port for target group to work.