Is this proxy setup realizable?

[Samuel Vogel]

Hey guys,

I am planning on using nginx to be a reverse proxy infront of more than 
ten real servers, each containing 10 virtual machines. These virtual 
machines all contain the same setup lamp setup hosting about a 100 
users/domains each.
This means as a total we have about 10.000 domains. As we provide low 
cost shared hosting on low cost servers, we can not switch the ip of a 
virtual machine between servers. So when we migrate a VM to a different 
physical server because of load reasons, it's IP changes as well.

This is why we would like to use nginx infront as a reverse proxy. It 
would then always know the corresponding IP for a virtual machine and 
reroute the requests.

With my current knowledge of nginx I would setup a virtual host for 
every VM we have and add all the domains it contains into the 
server_name variable. This would mean 100 virtual host with very long 
server_names, each containing 100 domains.

Additionally I would like to use the reverse proxy setup to sanitize the 
requests, protect the VMs from dos attacks and if a VM goes down route 
all requests to this VM to a static file like "we'll be back soon".

My question is, would this configuration be maintainable with nginx? Can 
it cope with long server_names and a rather strange setup like this? Or 
will it degrade my performance too much?

Thanks for your answers!

Regards,
Samy