alt Hacker NewsI mean, I like animals too, but in context it does make sense. The context was to treat them as "obtainable yet ultimately killable entities you keep as a group, not individuals", which cattle pretty much is. Unless you consider keeping cattle as draft animals, but I think that stopped being the main purpose a long time ago.
It got the point across, at a time where most people basically acquired servers, kept them until they died, and he was trying to push a development workflow where you constantly close("kill")/bring up new servers.
IMO, "make your servers fungible" is a better way to express the intent: slightly shorter, no metaphors, although "fungible" is a less common word. Maybe that's just me. (Edited to add: "make your tests fungible" has I think the wrong connotation; I think the original wording on the blog is about test executions -- and "make your test executions fungible" does seem like a good goal, similar to ACID guarantees for database transactions.)