Illusory latency due to trailing slash redirects

[Krixano]

Ok, so I have a legitimate question... why are servers even redirecting for something as dumb as a trailing slash anyways?


Christian Seibold

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‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Saturday, June 27, 2020 3:57 AM, solderpunk <solderpunk at SDF.ORG> wrote:

> I sent the following email (and many others, which will follow shortly)
> to the list last night, but SDF's mailserver was acting up and they
> never went through. I thought they'd appear eventually, but it appears
> not, so I'm resending them now. Apologies if double posts eventually
> appear.
>
> ----- Forwarded message from solderpunk solderpunk at SDF.ORG -----
>
> Date: Fri, 26 Jun 2020 15:47:57 +0000
> From: solderpunk solderpunk at SDF.ORG
> To: gemini at lists.orbitalfox.eu
> Subject: Illusory latency due to trailing slash redirects
>
> Gemini servers (and servers for any other protocol supporting relative
> URLs, including HTTP) will use redirects to get clients to add a
> trailing slash to a URL which maps to a directory on the server's
> filesystem. Handling this redirect is often invisible to the client
> user, with the result that what "looks and feels" like a single request
> is actually two immediately consecutive requests. This makes latency
> appear to be much worse than it actually is. Perhaps this underlies
> some people's perceptions that Gemini has unacceptable latency.
>
> This basic problem is unavoidable, but there are many small things
> client and server authors can do to minimise how often it happens:
>
> In general, the client can't add a missing trailing slash itself because
> it never knows if a given URL maps to something file-like or something
> directory-like. An interesting exception is the root of the server.
> Molly Brown and Jetforce (but not GLV-1.12556) both seem to redirect
> gemini.example.com to gemini.example.com/, making the loading of
> "homepages" feel slower than it needs to. I'm pretty sure it should be
> safe for clients to automatically append trailing slashes to URLs
> without paths.
>
> On the server side, server authors should take care when doing things
> like automatically generating directory listings to put trailing slashes
> in links to directories so that the redirect is not necessary.
>
> These measures together could cut perceived latency in half for a
> non-trivial proportion of Gemini requests, including the psychologically
> heavily weighted request of visiting a server's homepage.
>
> Cheers,
> Solderpunk