Why does Elastic Load Balancing report 'Out of Service'?

Question

I am trying to set up Elastic Load Balancing (ELB) in AWS to split the requests between multiple instances. I have created several images of my webserver based on the same AMI,

Answer 1

I got the same error, in my case had to copy the particular html file from s3 bucket to "/var/www/html" location. The same html referenced in load balancer path.

The issue resolved after copying html file.

Answer 2

I to faced same issue , i changed Ping Protocol from https to ssl .. it worked !

Go to Health Check  --> click on Edit Health Check -- > change Ping protocol from HTTPS to SSL

Ping Target SSL:443
Timeout 5 seconds
Interval    30 seconds
Unhealthy Threshold 5
Healthy Threshold   10

Answer 3

Health check is (by default) made by accessing index.html on each instance incorporated in load balancer. If you don't have index.html in document root of instance - default health check will fail. You can set custom protocol, port and path for health check when creating elastic load balancer.

Answer 4

In my case, the rules on security groups assigned to the instance and the load balancer were not allowing traffic to pass between the two. This caused the health check to fail.

Answer 5

I had a similar issue. The problem appears to have been caused due to my using a HTTP health check and also using .htaccess to password protect the site.

Answer 6

Finally I got this working. The issue was with the Amazon Security Groups, because I've restricted the access to port 80 to few machines on my development area and the load balancer could not access the apache server on the instance. Once the load balancer gained access to my instance, it gets In Service.

I checked it with tail -f /var/log/apache2/access.log in my instance, to verify if the load balancer was trying to access my server, and to see the answer the server is giving to the load balancer.

Hope this helps.