Tell HN: t.co is adding a five-second delay to some domains

>>xslowz+(OP)
Additional details I wrangled for this rabbit hole. I don't think it's t.co doing this intentionally, but rather poor handling of 'do you have our cookies or not'. Everyone in this thread _proving things_ without taking into account the complexity of the modern web.

   man curl
       -b, --cookie <data|filename>
              (HTTP) Pass the data to the HTTP server in the Cookie header. It is supposedly the data previously received from the server in a "Set-Cookie:" line.

----

Add that option to your curl tests.

    ---
    $ time curl -s -b -A "curl/8.2.1" -e ";auto" -L https://t.co/4fs609qwWt -o /dev/null | sha256sum 
    eb9996199e81c3b966fa3d2e98e126516dfdd31f214410317f5bdcc3b241b6a2  -

    real    0m1.245s
    user    0m0.087s
    sys     0m0.034s
    ---

    $ time curl -s -b -e ";auto" -L https://t.co/4fs609qwWt -o /dev/null | sha256sum 
    eb9996199e81c3b966fa3d2e98e126516dfdd31f214410317f5bdcc3b241b6a2  -

    real    0m1.265s
    user    0m0.103s
    sys     0m0.023s
    ---

    $ time curl -s -b -A "Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0" -e ";auto" -L https://t.co/4fs609qwWt -o /dev/null | sha256sum 
    eb9996199e81c3b966fa3d2e98e126516dfdd31f214410317f5bdcc3b241b6a2  -

    real    0m1.254s
    user    0m0.100s
    sys     0m0.018
    ---

>>Pengui+kK1
I can replicate this behavior fairly easily in a browser.

  1. Open incognito window in Chrome
  2. Visit https://t.co/4fs609qwWt -> 5s delay
  3. Open a second tab in the same window -> no delay
  4. Close window, start a new incognito session
  5. Visit https://t.co/4fs609qwWt -> 5s delay returns

>>ender7+s12
What is that attempting to prove or replicate?

Here's a simpler test I think replicates what I am indicating in GP comment, with regards to cookie handling:

Not passing a cookie to the next stage; pure GET request:

    $ time curl -s -A "Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0" -e ";auto" -L https://t.co/4fs609qwWt > nocookie.html

    real    0m4.916s
    user    0m0.016s
    sys     0m0.018s

Using `-b` to pass the cookies _(same command as above, just adding `-b`)_

    $ time curl -s -b -A "Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0" -e ";auto" -L https://t.co/4fs609qwWt > withcookie.html

    real    0m1.995s
    user    0m0.083s
    sys     0m0.026s

Look at the differences in the resulting files for 'with' and 'no' cookie. One redirect works in a timely manner. The other takes the ~4-5 seconds to redirect.

zlacker