One of my projects is an internal web app which we are putting behind a load balancer. As of now there is only one ec2 (will be more in production) and the load balancer is not able to reach the ec2-Instance.
The load balancer is setup to accept connections over port 448 and forward them to the ec2-Instance on port 80. The ec2-Instance's are listed in the load balancer in the console but they keep failing the health check.
To debug further I created a test ec2-Instance (54.68.255.208) through the console with a security group that allows connections from anywhere in the world on any port. I installed apache on it and had it serve the default page. I then created a new load balancer (http://lb-test-lb-512274268.us-west-2.elb.amazonaws.com/) that allows all traffic on tcp ports. I added the ec2-Instance to the load balancer, but for no apparent reason the health check fails even though I can connect to the ec2-Instance over port 80 with no problems.
Nobody else in our office has this issue but nobody else has any explanation for what is causing it. Does it sound like I'm missing anything here?
Best Answer
The best way to debug an ELB issue is to do the following:
Ensure the security groups on the instance(s) are setup to allow the incoming port (80)
Make sure your health check is setup correctly
tail -f(or similar) the logs of the instance(s) you're trying to add to the balancer.An example ping from the health checker in the instance logs:
Ensure the "Listener" configuration is correct: 80 to 80 (for example)