Outside of the big clouds just buying a 1 Year lease (say) on a dedicated server is so cheap that you'd not be saving much vs spot instances and with spot instances you need code to manage this and you're introducing risk of slowdowns. Probably not worth the trade off.
To illustrate a 128GB ram 20 core server with a 10Gbps NIC and some small SSD storage is probably going to cost you <$2000 USD for a years rental.
They've got usage that plummets 80% 2 days a week and the other 5 have a broad predictable time based pattern where usage drops ~66% judging by graph.
If that works out to same prices as keeping compute at literally your peak requirement level round the clock then something is very wrong somewhere. Maybe that issue is not in-house at blacksmith - perhaps spot pricing is a joke...but something there doesn't check out.
Loads of companies do scaling with much less predictable patterns.
>risk of slowdowns
Yeah you do probably want the scaling to be super conservative...but -80% fluctuation is a comically large gap to not actively scale
>To illustrate
Better view I'd say is: That chart looks like ~4.5 peak. So you're paying for 730 hours of peak capacity and using all of it about 90 hrs.
Given that they wrote a blog about this topic they probably have a good reason for doing it this way. Just doesn't really make sense to me based on given info
No, I'm not. I'm looking at the 5 day average across fleet graph right at the bottom. That shows very roughly 2/3 drop from peak to lowest, while the 80% is from the text as fleet wide.
>whereas renting the server is about half that per hour.
If you're at capacity only 90 out of 730 a month then paying 2x for spot to cover those peaks is a slam dunk
yeah, like the others have said, the tradeoff isn't really worth it for us as a business. spot instances also generally come with low qos guarantees (since they tend to be interruptible). tbf there are on-demand alternatives with better guarantees though
another thing to note is that we bootstrap the hosts, and tune them a decent amount, to support certain high-performance features which takes time and makes control + fixed-term ownership desirable
If their businessmodel is high performance runners and cheap cost they probably don't want to budge on speed, and once renting something fast on the cloud the costs run up quickly enough that they are probably just better off with a few more machines that pay themselves over time.
To illustrate a 128GB ram 20 core server with a 10Gbps NIC and some small SSD storage is probably going to cost you <$2000 USD for a years rental.