The Arrakis team did it with Haproxy, Reddis, and Memcached, but in a research operating system: http://people.inf.ethz.ch/troscoe/pubs/peter-arrakis-osdi14.pd

The Arrakis team did it with Haproxy, Reddis, and Memcached, but in a research operating system: http://people.inf.ethz.ch/troscoe/pubs/peter-arrakis-osdi14.pdf http://people.inf.ethz.ch/troscoe/pubs/peter-arrakis-osdi14.... BSD has had userland networking for a while: http://www.bsdcan.org/2014/schedule/events/447.en.html http://www.bsdcan.org/2014/schedule/events/447.en.html I'm not sure if there's anything comparable for Linux.