lets face it, almost all uses of the terms master/slave are used in cases where we actually mean primary/secondary, or active/passive.
master literaly means the one that issues commands and controls the execution context. slave means the one that executes the commands and returns its results to the master. suitable alternative terms are controller/worker. or manager/worker.
ironic that all of you with issues over changing the terms are probably using them incorrectly in the first place.