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
oh boy... -b takes an option which in your examples is -A and -e, then what follows is interpreted as a URL and you throw away the warnings:

  % curl -vgsSIw'> %{time_total}\n' -b -A "curl/8.2.1" https://t.co/DzIiCFp7Ti 2>&1 | grep '^\(* WARNING: \)\|\(Could not resolve host: \)\|>' 
  * WARNING: failed to open cookie file "-A"
  * Could not resolve host: curl
  curl: (6) Could not resolve host: curl
  * WARNING: failed to open cookie file "-A"
  > HEAD /DzIiCFp7Ti HTTP/2
  > Host: t.co
  > User-Agent: curl/8.1.2
  > Accept: */*
  > 
  > 0.013309
  > 0.112494

zlacker