A Reserved Instance is not an instance. Let me say that again. A Reserved Instance is not an instance.
If that sounds confusing, let’s take a step back and talk about what an instance is. Basically, an instance is someone else’s computer that you can rent. AWS would say an instance is a “virtual computing environment.” The “virtual” means you might really be getting part of a computer, or multiple computers wired together. For our purposes, “someone else’s computer” is good enough.
Returning to Reserved Instances, a Reserved Instance isn’t an instance, it’s a reservation. In other words, you’re not buying a specific computer, you’re buying a reservation for a type of computer. It’s like reserving a hotel room: the hotel doesn’t necessarily have a specific non-smoking room with a queen-sized bed earmarked for you, but they commit to having a room of that type available when you show up.
Why would you want to buy a Reserved Instance? Because it saves you money. Compared to paying as you go for whatever you use - what AWS calls On-Demand - using Reserved Instances can give you AWS savings of up to 72%.
Continuing with the hotel analogy, using On-Demand is like showing up to the hotel without a reservation and asking for the most expensive room. Actually, it’s probably worse than that, because chances are you don’t use one instance at a time, you use many instances to run your business. So it’s more like you’re in charge of a network of employees crisscrossing the country and all of them show up to the hotel and ask for the most expensive room whenever they need to stay anywhere.
Buying an AWS Savings Plan is like cutting a deal with the national hotel chain to get a flat rate discount across the board. Better than paying all On-Demand, for sure. So why even bother with Reserved Instances? Because the AWS savings from Reserved Instances are often bigger than those for Savings Plans. The catch is that it’s annoying and time-consuming to figure out the ideal Reserved Instance for every instance you use.
In this analogy, Reserved.ai is like Kayak for Reserved Instances. We scour all the available rates to find the best AWS savings opportunities based on the instances you already use. But unlike with Kayak, you don’t have to manually click through all the deals we find. We handle everything behind the scenes and just ask you to sign off on the purchase.
If you’d like to spend less time on cost management while maximizing your AWS savings, get in touch with us at firstname.lastname@example.org.