HTTP does a pretty good job staying out of everyone's way.

If you're reading this article, there's a solid chance it was delivered to you over HTTP. Even if you're reading this from an RSS reader or something. And you didn't even have to think about it!

"Not having to think about it" is certainly a measure of success for a given technology. By contrast, . I wish I didn't.

As the popular saying goes, there are only two hard problems in computer science: caching, off-by-one errors, and getting a Rust job that isn't cryptocurrency-related.

Today, we'll discuss caching! Or rather, we'll discuss... "request coalescing", or "request deduplication", or "single-flighting" - there's many names for that concept, which we'll get into fairly soon.

When I get a little bit too emotional about my current baby, the itch.io app, there's always a timely support ticket reminding me that it is currently, still a glorified game downloader.

However true that is, that doesn't mean it's easy! In the past year, I've had to account for a bunch of failure conditions that can happen, some of which I didn't realize were even possible. Let's review them, for fun!