This is my actual users set up.
> show users; { "_id" : "admin.super", "user" : "super", "db" : "admin", "roles" : [ { "role" : "root", "db" : "admin" } ] } { "_id" : "admin.nodebb", "user" : "nodebb", "db" : "admin", "roles" : [ { "role" : "clusterMonitor", "db" : "admin" } ] } > use nodebb switched to db nodebb > show users; { "_id" : "nodebb.nodebb", "user" : "nodebb", "db" : "nodebb", "roles" : [ { "role" : "clusterMonitor", "db" : "admin" }, { "role" : "readWrite", "db" : "nodebb" } ] }