AWS: Query regarding auto scaling

Question

I have gone through autoscaling documentation but that does not clarify my doubt.

I would like to understand what exactly happens when you add your ec2 instances to the auto scaling group.

When a new instance gets triggered does it just increases the compute capacity of the instance?

Does it just create a clone of the existing instances?

If I have an application running on two instances sharing the same filesystem, how does the 3rd instance which got spun as a part of autoscaling gets added to the existing cluster and how does it scale up the application load?

Thanks in Advance!

Answer 1

1. It launches additional instance, which you may add behind a load balancer when creating autoscaling group.

2. It will use AMI specified in launch configuration to launch new instances.

3. You need to make sure in AMI is attaching shared file system upon boot. Also, you need to create autoscaling with load balancer to share the load and have your all instances behind a load balancer.