HAProxy, NGINX and Rails anyone?

[Jon Singler]

I'm about to reveal my near total ignorance about load balancing, but
I'm doing so in hopes that someone can enlighten me a bit.

If you have a load balancer -- HAProxy, say -- on a machine with a
1Gig NIC to the internet, and it is balancing to, say, 4 web servers
which also have 1Gig NICs, won't the 4 web servers stand a pretty good
chance of overwhelming the load balancer? I.e., of getting backed up
because they are collectively pushing more data to HAProxy than
HAProxy can send out to the internet? (To make it more extreme, say
you had 20 web servers.)

Or is there some way that IP networking and/or the switches in data
centers sort this all out so it isn't a problem?

Just something I've long wondered about.

-Jon