With 2.0.1 we get:
This worked with MaxScale 1.4.3. It seems in 2.0.1 we have to specify the user and password on the command-line (after upgrade or if we do not rely on UNIX domain sockets only):
As the old internet socket based communication was put back in 2.0.1, we should put back processing of user and passwd settings from .maxadmin.
Side note: This KB article:
also needs clarifications on what is supposed to be recognized in .maxadmin file and in what exact 2.0.x versions.