How AWS load balancer will behave in following scenario?

Question

We have two instances added to load balancer. Each instance have 2 different applications running on different app servers(port 80 & 443). We have listeners to forward request on LB's port 80 & 443 to instance port 80 & 443 respectively. Load balancer health check is configured to ping on port 80.

Now if application running on port 443 died/crashed on instance 2, whether load balancer still continues to forward requests on port 443 of instance 2? (As instance will be in service because health check is configured for port 80)

Or

Will Load balancer come to know that no one is listening on port 443 for instance 2 and will it forwards all requests on port 443 to instance 1 from now?

Answer 1

Load balancer health check is configured to ping on port 80

This sentence say it all. If you have configured load balancer to check for health on port 80 it will consider both the instances as healthy in the scenario you mentioned. It will keep on sending requests on port 443 of instance 2 and keep on getting error response.