$  ab -c 10 -n 200 127.0.0.1:3000/
...
Percentage of the requests served within a certain time (ms)
  50%    420
  66%    421
  75%    422
  80%    422
  90%    423
  95%    424
  98%    426
  99%    428
 100%    432 (longest request)

$  ab -c 10 -n 200 -k 127.0.0.1:3000/
...
Percentage of the requests served within a certain time (ms)
  50%    205
  66%    205
  75%    206
  80%    206
  90%   1852
  95%   2258
  98%   2273
  99%   2450
 100%   2477 (longest request)

$ cat Gemfile
source "https://rubygems.org"
gem "puma"
gem "rack"
⛄️ 3.3.1 🚀 /private/tmp/e3f9bf2d7f5e861b6de95d7e48a1b5b0
$ cat config.ru
require 'rack'
response = ['200', {'Content-Type' => 'text/html'}, ['Hello, World!']]
app = Proc.new do |env|
  sleep 0.2
  response
end
run app
$ bundle exec puma -t5 -p 3000
Puma starting in single mode...
* Puma version: 6.4.2 (ruby 3.3.1-p55) ("The Eagle of Durango")
*  Min threads: 5
*  Max threads: 5
*  Environment: development
*          PID: 7434
* Listening on https://0.0.0.0:3000
Use Ctrl-C to stop

$ hey -c 10 -n 200 https://localhost:3000/
Summary:
  Total:	8.3877 secs
  Slowest:	2.4628 secs
  Fastest:	0.2005 secs
  Average:	0.3612 secs
  Requests/sec:	23.8445
  Total data:	2600 bytes
  Size/request:	13 bytes
Response time histogram:
  0.201 [1]	|
  0.427 [184]	|■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  0.653 [0]	|
  0.879 [0]	|
  1.105 [0]	|
  1.332 [0]	|
  1.558 [0]	|
  1.784 [0]	|
  2.010 [0]	|
  2.237 [0]	|
  2.463 [15]	|■■■