DDOS, multi-path, multi-az, dr, snapshots, hardware redundancy, elasticity, freedom from datacenter contracts, fiber contracts, driving to rack stuff, jammed fingers, staff costs, firmware bugs, bad hardware batches, cdn, compliance costs. I have more but I'll stop there.
It doesn't make sense at very small or large scales but it captures a hell of a lot of the middle.
Do you have any other recommendations for queue systems that can handle a million messages per minute (our use case)?
Almost all of the systems tested hit 17k / s (aside from NSQ) -- on a laptop. NATS (gnatsd) hits 0.2M per second, that's a magnitude above what you need and that's a brokered system, if your task fits with a brokerless one then nanomsg is yet another magnitude. I do not particularly see where the problem really is?
Thanks