The folks behind the NGINX web server have put up a highly self-congratulatory article on how the system was designed. "NGINX scales very well to support hundreds of thousands of connections per worker process. Each new connection creates another file descriptor and consumes a small amount of additional memory in the worker process. There is very little additional overhead per connection. NGINX processes can remain pinned to CPUs. Context switches are relatively infrequent and occur when there is no work to be done."
June 10, 2015
Inside NGINX: How We Designed for Performance & Scale
Read more at LWN