I'm having issues setting up HTTPS on AWS via a load balancer. I've managed to get as far as proxying my standard :80 server, via HTTPS on the load balancer, so requests to https://www.example.com are working. So if AWS can handle HTTPS traffic at the ELB level, do I actually need to start a separate web server to handle the HTTPS traffic, or can I just leave it at that?
What are the disadvantages of proxying HTTPS -> HTTP using an AWS load balancer?
Even without ELB, you don't need two web servers - Apache, nginx, IIS and other popular webservers can all serve HTTP and HTTPS at the same time.
That said, you can leave it the way you have it now, with one caveat - traffic between the ELB and your EC2 instance is unencrypted. As it's on Amazon's internal network, this is reasonably secure, but if you're transmitting stuff like credit cards and social security numbers, you'll want it encrypted all the way (especially if PCI compliance comes into play).