A $1k AWS mistake

Haha, yep we were lucky to catch this early! It could easily have gotten lost with everything else in the monthly AWS bill.

Came here to say the same, take my vote

    - DevOops

That was truly my hope with this post! Glad to hear that

I think it's been calculated that data transfer is the biggest margin product in all AWS catalog by a huge difference. A 2021 calculation done by Cloudflare [0] estimated almost 8000% price markup in EU and US regions.

And I can see how, in very big accounts, small mistakes on your data source when you're doing data crunching, or wrong routing, can put thousands and thousands of dollars on your bill in less than an hour.

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  0: https://blog.cloudflare.com/aws-egregious-egress/

I don't think its about profits, its about incentivising using as many AWS products as possible. Consider it an 'anti-lock-in fee'

Depends on various factors and of course the amount of money in question. I've had AWS approve a refund for a rather large sum a few years ago, but that took quite a bit of back and forth with them.

Crucial for the approval was that we had cost alerts already enabled before it happened and were able to show that this didn't help at all, because they triggered way too late. We also had to explain in detail what measures we implemented to ensure that such a situation doesn't happen again.

> Does Amazon refund you for mistakes

Hard no. Had to pay I think 100$ for premium support to find that out.

I presume it depends on your ability to pay for your mistakes. A $20/month client is probably not going to pony up $1000, a $3000/month client will not care as much.

Hahaha. I'll update the post once I hear back from them. One could hope that they might consider an account credit.

They do sometimes if you ask. Probably depends on each case though.

Reading all the posts about people who got bitten by some policies on AWS, I think they should create two modes:

- raw

- click-ops

Because, when you build your infra from scratch on AWS, you absolutely don't want the service gateways to exist by default. You want to have full control on everything, and that's how it works now. You don't want AWS to insert routes in your route tables on your behalf. Or worse, having hidden routes that are used by default.

But I fully understand that some people don't want to be bothered but those technicalities and want something that work and is optimized following the Well-Architected Framework pillars.

IIRC they already provide some CloudFormation Stacks that can do some of this for you, but it's still too technical and obscure.

Currently they probably rely on their partner network to help onboard new customers, but for small customers it doesn't make sense.

the gateway endpoints are free (s3 + dynamodb?), but the service endpoints are charged so that could be a reason why people don't use the service endpoints. but there doesn't seem to be a good reason for not using the service gateways. it also seems crazy that AWS charges you to connect to their own services without a public ip. also, i guess this would be less of an issue (in terms of requiring a public ip) if all of AWS services were available over ipv6. because then you would not need NAT gateways to connect to AWS services when you don't have a public ipv4 ip and I assume you are not getting these special traffic charges when connecting to the AWS services with a public ipv6 address.

Yes uploading into AWS is free/cheap. You pay per GB of data downloaded, which is not cheap.

You can see why, from a sales perspective: AWS' customers generally charge their customers for data they download - so they are extracting a % off that. And moreover, it makes migrating away from AWS quite expensive in a lot of circumstances.

Yes…?

Egress bandwidth costs money. Consumer cloud services bake it into a monthly price, and if you’re downloading too much, they throttle you. You can’t download unlimited terabytes from Google Drive. You’ll get a message that reads something like: “Quota exceeded, try again later.” — which also sucks if you happen to need your data from Drive.

AWS is not a consumer service so they make you think about the cost directly.

Made in California.

We are programmed to receive. You can check out any time you like, but you can never leave

Nine cents per gigabyte feels like cellphone-plan level ripoff rather than a normal amount for an internet service.

And people wonder why Cloudflare is so popular, when a random DDoS can decide to start inflicting costs like that on you.

You put a CDN in front of it and heavily cache when serving to external customers

That is the business model and one of the figurative moats: easy to onboard, hard/expensive (relative to on-boarding ) to divest.

Though important to note in this specific case was a misconfiguration that is easy to make/not understand in the data was not intended to leave AWS services (and thus should be free) but due to using the NAT gateway, data did leave the AWS nest and was charged at a higher data rate per GB than if just pulling everything straight out of S3/EC2 by about an order of magnitude (generally speaking YMMV depending on region, requests, total size, if it's an expedited archival retrieval etc etc)

So this is an atypical case, doesn't usually cost $1000 to pull 20TB out of AWS. Still this is an easy mistake to make.

the statement is about aws in general, and yes, you pay for bandwith

Yes. It’s not very subtle.

Thats a year salary but hey think about how much more complicated your work would be if you had to learn to self-host your infra!

Yeah imagine the conversation:

"I'd like to spend the next sprint on S3 endpoints by default"

"What will that cost"

"A bunch of unnecessary resources when it's not used"

"Will there be extra revenue?"

"Nah, in fact it'll reduce our revenue from people who meant to use it and forgot before"

"Let's circle back on this in a few years"

Personally I don't even understand why NAT gateways are so prevalent. What you want most of the time is just an Internet gateway.

There's nothing to gain in punching down

They made a mistake and are sharing it for the whole word to see in order to help others avoid making it.

It's brave.

Unlike punching down.

Examples?

It's not that it's technically impossible. The very simple problem is that there is no way of providing hard spend caps without giving you the opportunity to bring down your whole production environment when the cap is met. No cloud provides wants to give their customers that much rope to hang themselves with. You just know too many customers will do it wrong or will forget to update the cap or will not coordinate internally, and things will stop working and take forever to fix.

It's easier to waive cost overages than deal with any of that.

This might be speaking the obvious, but I think that the lack of half-decent cost controls is not intentionally malicious. There is no mustache-twirling villain who has a great idea on how to !@#$ people out of their money. I think it's the play between incompetence and having absolutely no incentive to do anything about it (which is still a form of malice).

I've used AWS for about 10 years and am by no means an expert, but I've seen all kinds of ugly cracks and discontinuities in design and operation among the services. AWS has felt like a handful of very good ideas, designed, built, and maintained by completely separate teams, littered by a whole ton of "I need my promotion to VP" bad ideas that build on top of the good ones in increasingly hacky ways.

And in any sufficiently large tech orgnization, there won't be anyone at a level of power who can rattle cages about a problem like this, who will want to be the one to do actually it. No "VP of Such and Such" will spend their political capital stressing how critical it is that they fix the thing that will make a whole bunch of KPIs go in the wrong direction. They're probably spending it on shipping another hacked-together service with Web2.0-- er. IOT-- er. Blockchai-- er. Crypto-- er. AI before promotion season.

The problem with hard caps is that there's no way to retroactively fix "our site went down". As much as engineers are loathe to actually reach out to a cloud provider, are there any anecdotes of AWS playing hardball and collecting a 10k debt for network traffic?

Conversely the first time someone hits an edge case in billing limits and their site goes down, losing 10k worth of possible customer transactions there's no way to unring that bell.

The second constituency are also, you know, the customers with real cloud budgets. I don't blame AWS for not building a feature that could (a) negatively impact real, paying customers (b) is primarily targeted at people who by definition don't want to pay a lot of money.

AWS would much rather let you accidentally overspend and then forgive it when you complain than see stories about critical infrastructure getting shut off or failing in unexpected ways due to a miscommunication in billing.

These topics are not advanced...they are foundational scenarios covered in any entry level AWS or AWS Cloud third-party training.

But over the last few years, people have convinced themselves that the cost of ignorance is low. Companies hand out unlimited self-paced learning portals, tick the “training provided” box, and quietly stop validating whether anyone actually learned anything.

I remember when you had to spend weeks in structured training before you were allowed to touch real systems. But starting around five or six years ago, something changed: Practitioners began deciding for themselves what they felt like learning. They dismantled standard instruction paths and, in doing so, never discovered their own unknown unknowns.

In the end, it created a generation of supposedly “trained” professionals who skipped the fundamentals and now can’t understand why their skills have giant gaps.

AWS just released flat-rate pricing plans with no overages yesterday. You opt into a $0, $15, or $200/mo plan and at the end of the month your bill is still $0, $15, or $200.

It solves the problem of unexpected requests or data transfer increasing your bill across several services.

https://aws.amazon.com/blogs/networking-and-content-delivery...

AWS just yesterday launched flat rate pricing for their CDN (including a flat rate allowance for bandwidth and S3 storage), including a guaranteed $0 tier.

https://news.ycombinator.com/item?id=45975411

I agree that it’s likely very technically difficult to find the right balance between capping costs and not breaking things, but this shows that it’s definitely possible, and hopefully this signals that AWS is interested in doing this in other services too.

I think it’s disingenuous to claim that AWS only offers delayed alerts and half-decent cost controls. Granted, these features were not there in the beginning, but for years now AWS, in addition to the better known stuff like strategic limits on auto scaling, allows subscribing to price threshold triggers via SNS and perform automatic actions, which could be anything including scaling down or stopping services completely if the cost skyrockets.

I've always been under the impression billing is async and you really need it to be synchronous unless cost caps work as a soft limit.

You can transfer from S3 on a single instance usually as fast as the instances NIC--100Gbps+

You'd need a synchronous system that checks quotas before each request and for a lot of systems you'd also need request cancellation (imagine transferring a 5TiB file from S3 and your cap triggers at 100GiB--the server needs to be able to receive a billing violation alert in real time and cancel the request)

I imagine anything capped provided to customers already AWS just estimates and eats the loss

Obviously such a system is possible since IAM/STS mostly do this but I suspect it's a tradeoff providers are reluctant to make

What is a bootstrapped dev?

We are also 100% customer-funded. AWS makes sense for us for the enterprise version of Geocodio where we are SOC2 audited and HIPAA-compliant.

We are primarily using Hetzner for the self-serve version of Geocodio and have been a very happy customer for decades.

VPC peering becomes ugly fast, once your network architecture becomes more complex. Because transitive peering doesn't work you're building a mesh of networks.

I'd say it's a racket for enterprise but it makes sense for small things. For example, a friend of mine, who's in a decent bit of debt and hence on the hunt for anything that can make some money, wanted to try making essentially a Replika clone for a local market and being able to rent an H100 for 2$ an hour was very nice. He could mess around a bit, confirm it's way more work than he thought and move on to other ideas for like 10$ :D

Assuming he got it working he could have opened service without directly going further in debt with the caviat that if he messed up the pricing model, and it took off, it could have annihilated his already dead finances.

I worked in a billing department, and learned to be healthily paranoid about such things. I want to regularly check what I'm billed for. I of course check all my bank accounts' balances at least once a day. All billing emails are marked important in my inbox, and I actually open them.

And of course I give every online service a separate virtual credit card (via privacy dot com, but your bank may issue them directly) with a spend limit set pretty close to the expected usage.

my understanding from reading this kind of threads is that there is no real way to enforce it and the provider makes no guarantees, as your usage can outpace the system that is handling the accounting and shutoff

You can with some effort, but cloud providers don't provide real-time information on how much you're spending. Even if you use spending alerts to program a hard cut-off yourself, a mistake can still result in you being charged for 6+ hours of usage before the alert fires.

Shut down everything? Including S3? There goes all your data.

Yes, but you have to program it. And there is a little bit of whack so it might be $51 or something like that.

Or just run bare metal + garage and call it a day.

If you use the AWS console, it's a tick box to include this.

The reason to not include the endpoint by default is because VPCs should be secure by default. Everything is denied and unless you explicitly configure access to the Internet, it's unreachable. An attacker who manages to compromise a system in that VPC now has a means of data exfiltration in an otherwise air gapped set up.

It's annoying because this is by far the more uncommon case for a VPC, but I think it's the right way to structure, permissions and access in general. S3, the actual service, went the other way on this and has desperately been trying to reel it back for years.

S3 Gateway endpoints break cross-region S3 operations. Changing defaults will break customers.

AWS is not going to enable S3 endpoints by default, and most of the thread is downvoting the correct explanations like thinking in terms of a small hobby VPC, not the architectures AWS actually has to support.

Why it should not be done:

1. It mutates routing. Gateway Endpoints inject prefix-list routes into selected route tables. Many VPCs have dozens of RTs for segmentation, TGW attachments, inspection subnets, EKS-managed RTs, shared services, etc. Auto-editing them risks breaking zero-trust boundaries and traffic-inspection paths.

2. It breaks IAM / S3 policies. Enterprises commonly rely on aws:sourceVpce, aws:SourceIp, Private Access Points, SCP conditions, and restrictive bucket policies. Auto-creating a VPCE would silently bypass or invalidate these controls.

3. It bypasses security boundaries. A Gateway Endpoint forces S3 traffic to bypass NAT, firewalls, IDS/IPS, egress proxies, VPC Lattice policies, and other mandatory inspection layers. This is a hard violation for regulated workloads.

4. Many VPCs must not access S3 at all. Air-gapped, regulated, OEM, partner-isolated, and inspection-only VPCs intentionally block S3. Auto-adding an endpoint would break designed isolation.

5. Private DNS changes behavior. With Private DNS enabled, S3 hostname resolution is overridden to use the VPCE instead of the public S3 endpoint. This can break debugging assumptions, routing analysis, and certain cross-account access patterns.

6. AWS does not assume intent. The VPC model is intentionally minimal. AWS does not auto-create IGWs, NATs, Interface Endpoints, or egress paths. Defaults must never rewrite user security boundaries.

Or go IPv6 and use an egress gateway instead.

https://docs.aws.amazon.com/vpc/latest/userguide/egress-only...

> This happens so often that the S3 VPC endpoint should be setup by default when your VPC is created.

It's a free service after all.

Now that AWS charges for public IPv4 addresses, is it still free if you need to access IPv4-only hosts?

I wonder why they don't...