Networking in the Cloud Fundamentals: Data Transfer Pricing

About Corey Quinn

Over the course of my career, I’ve worn many different hats in the tech world: systems administrator, systems engineer, director of technical operations, and director of DevOps, to name a few. Today, I’m a cloud economist at The Duckbill Group, the author of the weekly Last Week in AWS newsletter, and the host of two podcasts: Screaming in the Cloud and, you guessed it, AWS Morning Brief, which you’re about to listen to.

Transcript

Corey: Welcome to the AWS Morning Brief, specifically our 12-part mini series, Networking In The Cloud, sponsored by ThousandEyes. ThousandEyes recently released their state of the cloud benchmark performance report. They raced five clouds together and gave a comparative view of the networking strengths, weaknesses, and approaches of those various providers. Take a look at what it means for you. There's actionable advice hidden within, as well as incredibly useful comparative data, so you can start comparing apples to oranges instead of apples to baseballs. Check them out and get your copy today at snark.cloud/realclouds. That's snark.cloud/realclouds because Oracle cloud was not invited to participate.

Now, one thing that they did not bother to talk about in that report, is how much all of that data transfer across different providers costs. Today I'd like to talk about that, which is a bit of a lie because I'm not here to talk about it at all, I'm here to rant like a freaking lunatic for which I make no apologies whatsoever.

This episode is about data transfer pricing in AWS. Because honestly I need to rant about something and this topic is entirely too near and dear to my heart, given that I spend most of my time fixing AWS bills for interesting and various sophisticated clients.

Let's begin with a simple question. The answer to which is guaranteed to piss you off like almost nothing else. What does it cost to move a gigabyte of data in AWS? Think about that for a second. The correct answer, of course, is that nobody freaking knows. There is no way to get a deterministic answer to that question without asking a giant boatload of other questions.

Let me give you some examples, and before I do, I would like to call out that every number I'm about to mention applies only to us-east-1, because of course different regions in different places have varying costs, that every single one of these numbers is different in other places sometimes, but not always. Why? Because things are awful. I told you I was going to rant. I'm not apologizing for it at this point.

Let's begin simply and talk about what it takes to just shove a gigabyte of data into AWS. Now in most cases that's free. Inbound bandwidth is always free to AWS usually, until it passes through with load balancer or does something else but we'll get there. What does it cost to move data between two AWS regions? Great. The answer to that is, two cents per gigabyte in the primary regions, except there's one use case which gets slightly less. And that is moving between us-east-1 and us-east-2. One is in Virginia, two is in Ohio. That is half price at one cent per gigabyte. My working theory behind that is that it's because even data wants to get the hell out of Ohio.

Let's take it a step further. Let's say you were in an individual region. What does it cost to move data from 1-AZ to another? The documentation was exquisitely unclear, and I had to do some experiments with spinning up a few instances in otherwise empty AWS accounts, and using DD and Netcat to hurl data across various links to find out the answer and then wait till it showed up on my bill. The answer is it also costs 2 cents per gigabyte, the same cost as region to region. It's one cent per gigabyte out of an AZ and one cent per gigabyte in to an AZ. And that's right, it means you get charged twice. If you move 10 gigabytes, you are charged for 20 gigabytes on that particular metric.

This also has the fun ancillary side effect of meaning that moving data between Virginia and Ohio is cheaper to do that cross region transfer than it is to move that same data within an existing region. Oh wait, it gets dumber than that. What do load balancer data transfer fees look like? The correct answer is who the hell knows? On the old classic load balancers, it was 0.8 cents per gigabyte in or out to the internet and there was also an instance fee, but that's not what we're talking about today. Traffic from any existing load balancer today to something inside of an AZ is free unless it crosses an availability zone and then we're back into cross AZ data transfer territory and anything going from an availability zone to a load balancer costs one cent per gigabyte.

Now the newer load balancer generations, the ALDs and the NLDS, what does that cost? Nobody freaking knows because data throughput is just one of several dimensions that go into a load balancer capacity unit, which mean that what your data transfer price is going to look like is going to vary wildly because in this particular case, it's not data transfer itself. There's still that as it leaves, but you also have to pay for this as an additional through the load balancer fee, but it's blended into an LCU, so it's not at all obvious at times that that is in fact what you're being billed for.

In another episode of this mini series, we talked about global accelerator. Now there's a site to site VPN option, which they had for a while, but at re:Invent last year they announced a accelerated VPN option that leverages a lot of global accelerator technology to let that site to site VPN take advantage significantly of the global accelerator. Now what does that cost? I could not freaking tell you. There are, I am not exaggerating, five distinct billing line items, if you run an accelerated site to site VPN and of course, all of them cost you money. I am not exaggerating. That is the actual state of the world. It is incredibly annoying. It is so annoying that I'm going to have to take a break before I blow a blood vessel to tell you more about ThousandEyes instead.

So other than the cloud report, what is ThousandEyes? They effectively act as the global observer that watches the entire internet from a whole bunch of different listening posts around that internet and keeps track in near real time of what's going on, what's being slow, what providers are having issues and giving information directly to your folks on your side to be able to understand, adapt and mitigate those outages and slow downs. It helps immediately get to the point of is this a networking problem globally or is it our last crappy code deploy that broke things? If this sounds like something that might be useful for you or your team, I encourage you to check them out at thousandeyes.com. They're a fantastic company with a fantastic product and best of all their billing makes sense.

We're back to ranting again. That's right. My problem with the AWS data transfer pricing is not that it's shitty and complex, but also that it's expensive. Pricing largely has not changed since AWS...