控制nginx

支持以下信号，用 kill -<信号> <pid> 发过去就行。

TERM, INT : Quick shutdown

QUIT : Graceful shutdown

HUP : Configuration reload
Start the new worker processes with a new configuration
Gracefully shutdown the old worker processes

USR1 : Reopen the log files

USR2 : Upgrade Executable on the fly

WINCH : Gracefully shutdown the worker processes

非常好的是刷新配置 HUP， 不停机更新软件 USR2。真正做到了7x24。