I for one would prefer dom/sub, if we're going to go about rewriting perfectly good terminology that has been around for near a hundred years, but I don't think

I for one would prefer dom/sub, if we're going to go about rewriting perfectly good terminology that has been around for near a hundred years, but I don't think people are quite that open-minded yet (even though it helps remove the troubling idea of property rights on sentient beings). Naming is hard! Master/slave implies that there may be many slaves for one master, that the master tells the slave exactly what to do, and that slaves will not switch between masters on a whim. Leader/follower implies that there is no major difference between the two classes and that perhaps the "leader" is just a promoted follower ("leader election", etc.), that the leader is the first to hit a request or command, and that the followers may spontaneously decide to follow a different leader. Primary/secondary implies that the roles are equivalent, that requests are handled by the primaries, that there may be more than one instance of each role, and that secondaries are only used if a primary cannot deal with its task. Note that each use case is equally valid: m/s could be a read/write architecture for a database or electrical communications bus, l/f for a distributed simulation system spanning many nodes or a swarm of agents, and p/s for a redundant storage system. But, changing nomenclature seemingly for the hell of it is not usually a good idea. EDIT: "primary/replica" fits nicely as well.