Gitter ELB healthchecks are not checking application health

ELB uses HTTP response on HTTP:80/api/private/health_check/nginx to determine health of instances. But it returns 200 OK if nginx is healthy, not webapp.

We use ELB checks to determine the instance health and decide whether new ASG Launch Configuration deployment is successful. If ASG deems the deployment as success, it terminates the old instances which could cause outage if the health check was false positive.

It is therefore very important for ELB to use as precise health check as possible.