[manigandham]

> "it's pretty predictable"

It quite literally isn't, otherwise there would be no billing surprises in the first place. Your entire argument about predictability is counter to the problem of unpredictable charges.

> "just stop accepting new data"

This is still effectively data loss and a major problem in production. Customers would rather negotiate a bill than lose data.

> "Nobody cares if the spending limit is accurate to the cent. What people care about is not being surprised by huge invoices."

Then it's a soft-cap, and if that's all you want then you already have billing alarms. Otherwise what's the buffer amount? What overage is acceptable? Is there a real hard cap? What if that's reached? You didn't actually provide any solution here.

> "the glacier pricing scheme, or at lambda pricing ... It's almost impossible to know how much it's going to cost you ahead of time."

How so? AWS is completely transparent about pricing. The calculations for it might be hard, but that's an entirely different issue. There are plenty of tools you can use if you don't want to do it yourself, however this is another logically incongruent point where you claim billing is easy enough to calculate and predict accurately for caps yet simultaneously hard enough that it's "almost impossible".

[newaccount74]

You are twisting my words. I said it's easy to predict storage costs, to counter your claim that you'd need to delete data to stay within budget.

The biggest problem are mainly exorbitant bandwidth costs, and those are trivial to cap -- just stop serving requests.

Also, billing alarms are not a soft cap. They don't prevent you from waking up in the morning to a 5000€ bill.

> You didn't actually provide any solution here.

I'm commenting on the internet, I don't need to come up with a way for AWS to implement billing caps, especially since they have designed their service pricing in a way that makes estimates really hard.

But for most services, billing caps really aren't that hard, especially since the company we are discussing here (fly.io) apparently already allows billing caps if you prepay (according to other comments here).

[manigandham]

> "it's easy to predict storage costs"

You're just repeating this. Predictable is the opposite of surprise.

Even if storage use was very stable, so what? The overall bill is the problem so where the charges come from doesn't matter, only that eventually a limit is crossed. An overage is still an overage and the only way for billing to stop immediately is to delete and drop everything. This is the fundamental issue that you're not considering. It's what happens at the limit, not about how you get there.

> " billing alarms are not a soft cap"

Soft caps that don't actually stop anything are effectively nothing more than billing alarms. What else is their purpose?

> "I don't need to come up with a way for AWS to implement billing caps"

I didn't ask for implementation, I'm inquiring as to what logically is supposed to happen in the scenarios that occur based on your proposed "pretty simple" solution. If you can't answer then it's not so simple is it? You either haven't thought it through entirely to conclude that it's not actually possible to do that way.

> "designed their service pricing in a way that makes estimates really hard"

How so? You also keep repeating this without evidence. How is providing numbers on exactly what they charge for make it difficult? It's as transparent as it gets. They also have a calculator on their site. What more are you expecting?

> "for most services, billing caps really aren't that hard"

The nature of the service changes everything. Fly.io doesn't have billing caps, they just stop the apps when the credits run out and eat the bandwidth cost for now. The economics of scale can change that answer drastically, however even Fly repeats what I've said before: "the majority of people want their stuff to stay up" and "shut it down so you don't get billed" is usually not the preferred solution compared to negotiating a large bill.

[newaccount74]

> I'm inquiring as to what logically is supposed to happen in the scenarios that occur based on your proposed "pretty simple" solution.

Here's the simplest solution: If the limit is reached, stop serving requests, stop accepting new data, but don't delete any data. Allow static storage costs to go over the limit. That is probably what 99% of people who ask for a budget cap want, and it's the most logical thing to do because typically 99% of the charges are for bandwidth/requests/processing and only 1% for storage. If I set a limit at 10€ and amazon ends up charging me 10.2€ I can live with that.

The next simplest solution would be to look at how much is currently stored, multiply that with the storage cost per hour, multiply that with the remaining hours in the month, then subtract that from the monthly budget, and stop serving requests or accepting new data as soon as this lower limit is reached. This will guarantee that you never go over the limit without having to delete data. If data in storage is deleted before the end of the month, you'll end up spending less than the limit.

Now if you consider this basic math too complicated for a software engineer making $300000 a year, you could do something even simpler: allow the customer to set a limit on each resource. Eg. let the customer say, I want to limit S3 to 100GB of storage and 5TB of bandwidth and 2 million requests (or whatever). Of course that would be a bit of a hassle for the customer, but it would be very effective at preventing surprise charges.

> the majority of people want their stuff to stay up

At any cost? That's unlikely. I'm pretty sure that every company has some limit where they'd prefer the service to be down rather than pay the bill.

But if you go back up the thread you'll see that this discussion is about hobby users and tinkerers, and people who just sign up to try out the tech. These people absolutely want a hard cap on potential charges, and if you don't offer that you might scare them away.