Boss/Minion

If it’s referring to something like a mother/daughter circuitboard, I’ll use that. If it’s a host/client connection, I’ll use that. If it’s a primary/backup redundancy situation, I’ll use that. And those are just a few examples. There is rarely a good reason to use master/slave nowadays, since most situations already have better descriptors to begin with.

What's wrong with primary/secondary or main/alternate!?

Remember when we thought being overly politically correct to absurd levels was a bad thing? That said, Dom/Sub, I'd be down for that. Same meaning, different wording, and now it's also a sex reference.

Cargo Mommy module for Rust comes to mind for me.

https://faultlore.com/cargo-mommy/book/

We're using server and agent, but im also a proponent of "captain" and "crew"

Eh it's just words and they are more common than just computers every time I work on my cars I sometimes might have to bleed the slave cylinder or fill the master cylinder when doing brake work

Leader / Follower

well, i didn't know that computer hardware could be consenting and engaged with with the BDSM community at large.

Personally i just like master/slave because it's really fucking obvious how things are supposed to work. Outside of that there are some more specific terminologies that work better in specific applications. Leader follower is pretty cringe, but mostly gets the point across. Main and sub is already established lingo in the electrical field from what i understand.

I prefer to use Main/Sub terminology. It also works without needing to change any acronyms.

Main/secondary

Prime/secondary/tertiary etc

Not more wokism! Next they'll be demanding we stop talking about executing a child!

We agreed on Primary/Secondary and Primary/Replica already. Sorry.

Okay but what if I’m in a server room full of switches.

It is changing, albeit slowly. In git the default branch was changed from master to main.

In high availability we use primary and secondary, or many other versions of the same idea (main/secondary, etc).

Not sure how disks are handled these days but I haven't seen the master/slave terminology in those since my first CD burner