I want to setup an nginx server that will be used as a publicly accessible front-end webserver to reverse proxy and load-balance other apache/nginx servers that are serving PHP and django apps, and are configured with private IPs, and each is running in a different virtual machine.
Is this going to have a significant performance decrease compared to having the back-end servers publicly accessible instead?
What about SSL certificates for each domain? Do I need to have them configured in the front-end server or in the back-end servers? Does it matter where they are configured?