[donavanm]

I've helped build and run similar distributed systems with deep load balancing and network interactions. There are some packages out there that do bits and pieces of the problem. I don't know of anything COTS that is a suitable like for like replacement of the core components, much less a suitable system . On top of that, as Luca mentioned, you almost always get in to deep interactions between L3/4/5/7 and end up building bespoke logic that's tailored to the business or application needs. A trivial example would be the coupling from IP address assignment/announcement, to TLS cert, to SNI headers, to active customers, to application instance routing.