You are still thinking about this as an API, with for example JavaScript and some AJAX. The use case here is zone apex static website hosting: if you go to http://mycompany.com/ and get a 500 error, the user is just going to be staring at an error screen... there will be no JavaScript, and the browser will not retry. As I actually explicitly said multiple times: for an API that is a perfectly reasonable thing to have, but for static website hosting it just doesn't fly.
Oh I see what you mean, you're concerned about the first bytes to the browser being faulty. Well, that 2% error rate is spread out across the total of requests, the likelihood of a user getting a 500 on his first hit should be significantly less then 2%. (but it does seem like it will still be way too high)
Very valid point saurik, thanks for pointing out the extent of the problem. It is a dilemma. Seems kind of silly to have an instance just for the first hit to go through reliably for visitors, goddamit Amazon.
Edit: Wait a minute, maybe this could be solved with custom error pages which I think they support. :P
You're going to need to explain how the requests would differ. If anything I'd expect image files to be more cache-friendly and have fewer visible failures than the critical html files. An image might have a 2% failure rate once or twice plus fifty error-free cache loads, while an html page might have 2% failure every single click.
