1.Ngnix進程控制
控制正在運行ngnix是通過發送信號來完成，主要有以下一些信號
nginx –s stop ：Stops the daemon immediately (using the TERM signal).
nginx –s quit ：Stops the daemon gracefully (using the QUIT signal).
nginx –s reopen ：Reopens the log files.
nginx –s reload ：Reloads the configuration
nginx -t : Test Configuration File
nginx –g "timer_resolution 200ms"; 指定新的配置項
2. 將Nginx作爲系統服務運行（System Service）
爲了讓Ngnix隨系統啓動，需要將它設置爲系統服務
System V
System V中系統服務是由init進程來管理，系統服務分爲不同的級別（Runlevel State）：
| 0 | System is halted |
| 1 | Single-user mode (rescue mode) |
| 2 | Multiuser mode, without NFS support（Debian and Ubuntu 默認級別） |
| 3 | Full multiuser mode（Red Hat，Fedora，CentOS6 默認級別） |
| 4 | Not used |
| 5 | Graphical interface mode（Red Hat and Fedora 默認級別） |
| 6 | System reboot |
centos 6 /etc目錄中有不同級別服務對應的啓動腳本，這些目錄中腳本都是軟鏈接到/etc/init.d目錄
編寫sysv script ，系統服務啓動腳本通常在系統啓動，service httpd start ，/etc/init.d/httpd start 時被調用
將Nginx做成System V需要3個步驟
1.編寫Sysv 腳本: /etc/init.d/nginx
#!/bin/sh
#
# nginx - this script starts and stops the nginx daemon
#
# chkconfig: - 85 15
# description: Nginx is an HTTP(S) server, HTTP(S) reverse \
# proxy and IMAP/POP3 proxy server
# processname: nginx
# config: /etc/nginx/nginx.conf
# config: /etc/sysconfig/nginx
# pidfile: /var/run/nginx.pid
# Make sure to properly indicate the full path of your Nginx binary and conf. file here
nginx="/usr/local/nginx/sbin/nginx"
prog=$(basename $nginx)
NGINX_CONF_FILE="/usr/local/nginx/conf/nginx.conf"
pid_file="/usr/local/nginx/logs/nginx.pid"
get_pid(){
cat "$pid_file"
}
is_running(){
[ -f "$pid_file" ] && ps $(get_pid) > /dev/null 2>&1
}
start() {
if [ ! -x $nginx ];then
echo "$nginx is not executable.."
exit 3
fi
if [ ! -f $NGINX_CONF_FILE ];then
echo "$NGINX_CONF_FILE is not exist"
exit 4
fi
if is_running;then
echo "$prog is Already Running..."
else
echo -n $"Starting $prog: "
$nginx -c $NGINX_CONF_FILE
retval=$?
if [ $retval -ne 0 ];then
echo "Unable to start $prog"
exit 5
fi
echo "$prog Started"
fi
}
stop() {
if is_running;then
echo -n $"Stopping $prog: "
kill -s QUIT "$(get_pid)"
retval=$?
if [ $retval -ne 0 ];then
echo "Unable to stop $prog"
fi
echo "$prog Stopped"
fi
}
restart() {
configtest || return $?
stop
sleep 1
start
}
reload() {
configtest || return $?
echo -n $"Reloading $prog: "
killproc $nginx -HUP
RETVAL=$?
echo
}
force_reload() {
restart
}
configtest() {
$nginx -t -c $NGINX_CONF_FILE
RETVAL=$?
echo
}
force_reload() {
restart
}
configtest() {
$nginx -t -c $NGINX_CONF_FILE
}
status() {
if is_running;then
echo "Running"
else
echo "Stopped"
exit 1
fi
}
case "$1" in
start)
$1
;;
stop)
$1
;;
restart|configtest)
$1
;;
reload)
$1
;;
status)
$1
;;
*)
echo $"Usage: $0 {start|stop|status|restart|reload|configtest}"
exit 2
esac2.將nginx加入到系統默認啓動級別中
[[email protected] ~]# chkconfig nginx on
3. 檢查nginx 是否在對應啓動級別中（在對應的rc3.d中有軟鏈接）
[[email protected] ~]# chkconfig --list nginx
Nginx 0:off 1:off 2:on 3:off 4:on 5:on 6:off
Systemd
CentOS 7的服務systemctl腳本存放在：/usr/lib/systemd/，有系統（system）和用戶（user）之分，即：/usr/lib/systemd/system ，/usr/lib/systemd/user
每一個服務以.service結尾，一般會分爲3部分：[Unit]、[Service]和[Install]，具體內容如下：
[Unit] Description=nginx Documentation=http://nginx.org/en/docs/After=network.target remote-fs.target nss-lookup.target [Service] Type=forking PIDFile=/usr/local/nginx/logs/nginx.pid ExecStartPre=/usr/local/nginx/sbin/nginx -t -c /etc/nginx/nginx.conf ExecStart=/usr/local/nginx/sbin/nginx -c /etc/nginx/nginx.conf ExecReload=/usr/bin/kill -s HUP $MAINPID ExecStop=/usr/bin/kill -s QUIT $MAINPID PrivateTmp=true [Install] WantedBy=multi-user.target
2. 優雅地升級Ngnix(Upgrading Nginx gracefully )
複製新版本nginx到/usr/local/nginx/sbin/中替換舊文件
查找正在運行舊版本nginx master進程的進程號 ps x | grep nginx | grep master
向舊進程發送USR2信號：kill –USR2 pid, 此信號會讓舊nginx rename /usr/local/nginx/logs/nginx.pid成/usr/local/nginx/logs/nginx.pid.old 並啓動新nginx二進制文件。此時將會有2個nginx實例運行，一起處理請求
kill –WINCH oldPid 使舊nginx的worker進程優雅退出（舊nginx master進程還在）
kill –QUIT oldPid 使舊nginx的master進程也退出