I really wish Redis wouldn't use the "master/slave" terminology. Primary/replica or even Master/replica are better terms. I know I'll probably get flamed for saying this, but it's a pox on a project that I otherwise very much love.
This terminology has been used for a long time in computing. It's immediately recognised by everyone and in no way endorses human slavery. I'm getting quite fed up of the OTT political correctness movement in tech. Out of interest, what is your opinion on male/female USB connectors? Does one deserve to get fired if they make a joke about "big dongles"?
The term "slave" isn't even a good technical term. It would be better to call it a follower or replica which better approximates it's actual role. Not only is it "politically correct" it's also "technically correct", the best kind of correct.