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- Hacker News
- I don't understand why en-US and en-GB should be treated as the same. Wouldn't this result in American visitors seeing words like colour since the wrong English page would be served.by charcircuit
- "If the origin response does not include a Vary header, Cloudflare caches the response normally"[1]
"If one response omits it, Cloudflare could cache that response without the variance needed to keep it isolated."[2]
Will that non-Vary cache object front-run any Vary-segmented cache objects?
If so, probably worth adding a snippet rule to ensure every response has a Vary header?
1: https://developers.cloudflare.com/cache/concepts/vary/#how-v...
2: https://blog.cloudflare.com/vary-support/#how-a-response-mov...
by rob-olmos - If this surprises you, remember that Cloudflare doesn't cache HTML by default.by badlibrarian
- I had not actually realized what a mess Vary is.
Wow, sometimes I think it's amazing the web works at all!
by jrochkind1 - Is Vary really that ugly?
I’d say that it forces you to maybe parse and understand the headers that vary header.
Accept-Language is supposed to be parsed and matched according to RFC4647 in one of 3 ways. That part is rather complex, but it’s not Vary’s fault.
by jiehong - I just wish CF would enable Enterprise functionality to lower (paid) tiers as they promised a year ago yet haven’t delivered on.
https://blog.cloudflare.com/enterprise-grade-features-for-al...
Like Prefetch: https://developers.cloudflare.com/speed/optimization/content...
by tiffanyh - Wow this brings back memories. Over twenty years ago I added Vary support to various mod_cache submodules for Apache 2.0, and it was way too high a pain to reward ratio. It just uncovered so many user agent bugs and crazy backends. I remember arguments about being able to cache variable based on non-literal virtual headers (e.g. a geo location header), and a crazy request to Vary based on "Date:" ... which makes absolutely no sense. The whole thing was just too clever for its own good. It's no surprise that language selection ended up in URLs (/en-US/..) rather than "Vary: Accept-Lang" features.by colmmacc
- I've been wanting this from Cloudflare for years.
The classic problem here is if you do that thing where user agents that send "accept: text/html" get HTML, while user agents that don't get JSON or some other format.
This used to be impossible to deploy behind Cloudflare caching, because they ignored the Vary header on anything other than images - so you risked caching the JSON version and then serving it up to someone who was expecting HTML.
(Independent of the Cloudflare feature I ended up deciding never to use that pattern, because I prefer having URL that predictably returns HTML or JSON - I add a .json suffix to my apps to serve JSON instead.)
by simonw