zlacker

>>pul+(OP)
> Vertical scaling — a bigger, exponentially more expensive server

This is in practice not true at all. Vertical scaling is typically a sublinear cost increase (up to a point, but that point is a ridiculous beast of a machine), since you're (typically) upgrading just the CPU and/or just the RAM or just the storage; not all of them at once.

There are instances where you can get nearly 10x the machine for 2x the cost.

>>margin+lu
Disagree- typically vertical scaling is lumpy, and even worse- CPU and RAM upgrades are typically not linear, because you're limited by the number of slots/sockets and the manufacturers intentionally charge higher (expoentially) prices for the largest RAM and fastest CPUs.

>>dekhn+UG
Kafka is also a system that can make pretty good general use of more CPUs and more storage, but doesn't have much need for RAM. Tying the CPU and RAM together whether by CPU model or cloud vendor offerings is annoying if you're trying to scale only vertically.