Amazon Web Services (AWS) Hardware
Unlike most of its competitors, Amazon builds its hardware infrastructure from commodity components. Commodity, in this case, refers to using equipment from lesser-known manufacturers who charge less than their brand-name competitors. For components for which commodity offerings aren't available, Amazon (known as a ferocious negotiator) gets rock-bottom prices.
On the hardware side of the AWS offering, Amazon's approach is clear: Buy equipment as cheaply as possible. But wait, you may say, won't the commodity approach result in a less reliable infrastructure? After all, the brand-name hardware providers assert that one benefit of paying premium prices is that you get higher-quality gear.
Well . . . yes and no. It may be true that premium-priced equipment (traditionally called enterprise equipment because of the assumption that large enterprises require more reliability and are willing to pay extra to obtain it) is more reliable in an apples-to-apples comparison. That is, an enterprise-grade server lasts longer and suffers fewer outages than its commodity-class counterpart.
The issue, from Amazon's perspective, is how much more reliable the enterprise gear is than the commodity version, and how much that improved reliability is worth. In other words, it needs to know the cost-benefit ratio of enterprise-versus-commodity.
Making this evaluation more challenging is a fundamental fact: At the scale on which an Amazon operates (remember that it has nearly half a million servers running in its AWS service), equipment — no matter who provides it — is breaking all the time.
If you're a cloud provider with an infrastructure the size of Amazon's, you have to assume, for every type of hardware you use, an endless round of crashed disk drives, fried motherboards, packet-dropping network switches, and on and on.
Therefore, even if you buy the highest-quality, most expensive gear available, you'll still end up (if you're fortunate enough to grow into a very large cloud computing provider like, say, Amazon) with an unreliable infrastructure.
Put another way, at a very large scale, even highly reliable individual components still result in an unreliable overall infrastructure because of the failure of components, as rare as the failure of a specific piece of equipment may be.
The scale at which Amazon operates affects other aspects of its hardware infrastructure as well. Besides components such as servers, networks, and storage, data centers also have power supplies, cooling, generators, and backup batteries. Depending on the specific component, Amazon may have to use custom-designed equipment to operate at the scale required.
Think of AWS hardware infrastructure this way: If you had to design and operate data centers to deal with massive scale and in a way that aligns with a corporate mandate to operate inexpensively, you'd probably end up with a solution much like Amazon's. You'd use commodity computing equipment whenever possible, jawbone prices down when you couldn't obtain commodity offerings, and custom-design equipment to manage your unusually large-scale operation.