kill 信号

HUP - reloads config file and gracefully restart all workers. If the "preload_app" directive is false (the default), then workers will also pick up any application code changes when restarted. If "preload_app" is true, then application code changes will have no effect; USR2 + QUIT (see below) must be used to load newer code in this case. When reloading the application, Gem.refresh will be called so updated code for your application can pick up newly installed RubyGems. It is not recommended that you uninstall libraries your application depends on while Unicorn is running, as respawned workers may enter a spawn loop when they fail to load an uninstalled dependency.

INT/TERM - quick shutdown, kills all workers immediately

QUIT - graceful shutdown, waits for workers to finish their current request before finishing.

USR1 - reopen all logs owned by the master and all workers See Unicorn::Util.reopen_logs for what is considered a log.

USR2 - reexecute the running binary. A separate QUIT should be sent to the original process once the child is verified to be up and running.

WINCH - gracefully stops workers but keep the master running. This will only work for daemonized processes.

TTIN - increment the number of worker processes by one

TTOU - decrement the number of worker processes by one