On Nexuses (2015)
A maintenance nexus does for humans what an integration nexus does for programs; it provides a way for a human to get into the internals of a system and inspect and modify it as they need. Although I am unfamiliar with Erlang, I gather that the Erlang runtime provides some sort of maintenance nexus, in which one can connect to an Erlang program and obtain some manner of command line, by which the current state of the system can be manipulated from the inside out. The rejection of maintenance nexuses is much rarer than the rejection of integration nexuses; humans don’t want to learn a whole new “inner system” command line to deal with a program’s complicated innards (SQL databases may be an example, though; many administrative commands must be performed from an SQL command line, not an OS command line).
Source: www.devever.net