AWS EC2 instances are "Out of Service" after getting registered with ELB

Question

I am facing a problem in AWS. I am creating and registering an instance with an ELB. Though it is getting registered, it is not passing through the health check and showing Out-of-Service. The error reason is "Instance has failed at least the Unhealthy Threshold number of health checks consecutively".

My health check values are as follows:

Ping Target: TCP:80
Timeout: 10 seconds
Interval: 24 seconds
Unhealthy Threshold: 6
Healthy Threshold: 10

Appreciate your help.

Thanks,

Chandan

Answer 1

Is your instance behind the ELB running a web server ? If it is does it return an '200' (OK) ? If not then that's your problem.

If you are running a web service that returns a 200, is your security group open to the ELB? Meaning the ELB's source security group has to allowed into your instance's security group.

Answer 2

Make sure you application is running and not throwing any exception. In my case, it was node application
1. right click on 'EC2 > Load Balancer > ' and select on 'Edit health check'
2. change the protocol from https to tcp
3. Click on instance tab and status was inService