Ranch aims to provide everything you need to accept TCP connections
with a small code base and low latency while being easy to use
directly as an application or to embed into your own.

Ranch provides a modular design, letting you choose which transport
and protocol are going to be used for a particular listener. Listeners
accept and manage connections on one port, and include facilities to
limit the number of concurrent connections. Connections are sorted
into pools, each pool having a different configurable limit.

Ranch also allows you to upgrade the acceptor pool without having to
close any of the currently opened sockets.

WWW: https://github.com/extend/ranch