Many different AWS services use EC2 instances and you can understand that from the pricing pages.
Basically it's a multi-instance architecture (and not the more familiar multi-tenant approach that I personally use for most web applications).
When an AWS customer creates a new resource, internally AWS has to spin up a new EC2 instance, configure it, monitor its status and apply security patches and updates.
Does anyone know how do they connect to the VM to configure it?
Do they use SSH to connect or another protocol?
Or they use some kind of agent installed on the VM on first installation in order to apply the updates and changes?
Note: this question doesn't want to discuss the details of managing a database, I just want to know how AWS applies and updates the configuration of the EC2 instances when they offer a "managed" service (any service).
