nginx 信号量

nginx支持的信号量

TERM, INT	fast shutdown
QUIT		graceful shutdown
HUP			changing configuration, keeping up with a changed time zone (only for FreeBSD and Linux), starting new worker processes with a new configuration, graceful shutdown of old worker processes
USR1		重载日志文件
USR2		升级可执行文件，平滑升级，热升级
WINCH		graceful shutdown of worker processes

详细请见官网：http://nginx.org/en/docs/control.html