3人居るんだ…
$ RAILS_ENV=development bundle exec puma -C config/puma.rb &
[21439] Puma starting in cluster mode...
:
[21439] * Listening on http://127.0.0.1:3000
[21439] Use Ctrl-C to stop
[21439] - Worker 0 (PID: 21473) booted in 0.01s, phase: 0
[21439] - Worker 1 (PID: 21483) booted in 0.01s, phase: 0
$ lsof -ni :3000
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
bundle 21439 zunda 5u IPv4 241540 0t0 TCP 127.0.0.1:3000 (LISTEN)
bundle 21473 zunda 5u IPv4 241540 0t0 TCP 127.0.0.1:3000 (LISTEN)
bundle 21483 zunda 5u IPv4 241540 0t0 TCP 127.0.0.1:3000 (LISTEN)