需求：
旧的nginx版本：
root@mysql243:~# ll /usr/local/|grep nginx
lrwxrwxrwx 1 root root 25 2014-03-11 19:03 nginx -> /usr/local/nginx-1.4.2-gz/
打算升级到最新的nginx-1.6.2
1.使用初始化脚本nginx_install.sh 安装新版nginx-1.6.2
cp nginx.conf /usr/local/nginx-1.6.2/conf/ #拷贝旧的nginx.conf
cp -a sites /usr/local/nginx-1.6.2/conf/
#先检查语法是否错误
root@mysql243:~# /usr/local/nginx-1.6.2/sbin/nginx -t -c /usr/local/nginx-1.6.2/conf/nginx.conf
nginx: the configuration file /usr/local/nginx-1.6.2/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/nginx-1.6.2/conf/nginx.conf test is successful
2.mv /usr/local/nginx/sbin/nginx /usr/local/nginx/sbin/nginx.old
3.拷贝重编译的nginx
cp /usr/local/nginx-1.6.2/sbin/nginx /usr/local/nginx/sbin/
4.平滑的升级nginx二进制文件
kill -USR2 `cat /usr/local/nginx/logs/nginx.pid`
root 35568 1.0 0.0 30588 2980 ? S 16:30 0:00 nginx: master process /usr/local/nginx/sbin/nginx
nobody 35569 2.0 0.0 47560 18408 ? S 16:30 0:00 nginx: worker process
nobody 35570 1.0 0.0 47560 18408 ? S 16:30 0:00 nginx: worker process
nobody 35571 4.0 0.0 47984 19264 ? S 16:30 0:00 nginx: worker process
nobody 35572 2.0 0.0 47560 18408 ? S 16:30 0:00 nginx: worker process
nobody 35573 2.0 0.0 47832 19040 ? S 16:30 0:00 nginx: worker process
nobody 35574 1.0 0.0 47560 18408 ? S 16:30 0:00 nginx: worker process
nobody 35575 1.0 0.0 47560 18408 ? S 16:30 0:00 nginx: worker process
nobody 35576 1.0 0.0 47560 18392 ? S 16:30 0:00 nginx: worker process
root 35581 0.0 0.0 7640 1016 pts/12 S+ 16:30 0:00 grep --color=auto nginx
root 60574 0.0 0.0 30572 956 ? Ss Dec22 0:00 nginx: master process /usr/local/nginx/sbin/nginx
nobody 60575 0.9 0.0 49652 9800 ? S Dec22 125:44 nginx: worker process
nobody 60576 0.9 0.0 47088 11604 ? S Dec22 125:37 nginx: worker process
nobody 60577 0.9 0.0 47444 7908 ? S Dec22 125:33 nginx: worker process
nobody 60578 0.9 0.0 47160 11592 ? S Dec22 127:54 nginx: worker process
nobody 60579 0.9 0.0 47380 7764 ? S Dec22 126:20 nginx: worker process
nobody 60580 0.9 0.0 47452 12496 ? S Dec22 127:52 nginx: worker process
nobody 60581 0.9 0.0 48204 9192 ? S Dec22 127:09 nginx: worker process
nobody 60582 0.9 0.0 47280 11932 ? S Dec22 126:26 nginx: worker process
5.从容关闭旧版本的worker进程（等待关闭worker进程，可能需要处理一小会）
kill -WINCH `cat /usr/local/nginx/logs/nginx.pid.oldbin`
root 35568 0.0 0.0 30588 2980 ? S 16:30 0:00 nginx: master process /usr/local/nginx/sbin/nginx
nobody 35569 2.2 0.0 51340 22680 ? S 16:30 0:00 nginx: worker process
nobody 35570 0.0 0.0 47832 18940 ? D 16:30 0:00 nginx: worker process
nobody 35571 1.3 0.0 47984 19484 ? S 16:30 0:00 nginx: worker process
nobody 35572 0.5 0.0 47832 19128 ? S 16:30 0:00 nginx: worker process
nobody 35573 1.0 0.0 48100 19536 ? S 16:30 0:00 nginx: worker process
nobody 35574 0.0 0.0 47560 18476 ? S 16:30 0:00 nginx: worker process
nobody 35575 0.0 0.0 47560 18476 ? S 16:30 0:00 nginx: worker process
nobody 35576 0.0 0.0 47832 18972 ? D 16:30 0:00 nginx: worker process
root 35601 0.0 0.0 7640 1012 pts/12 S+ 16:30 0:00 grep --color=auto nginx
root 60574 0.0 0.0 30572 956 ? Ss Dec22 0:00 nginx: master process /usr/local/nginx/sbin/nginx
nobody 60575 0.9 0.0 48576 9016 ? D Dec22 125:45 nginx: worker process is shutting down
nobody 60576 0.9 0.0 46940 11500 ? D Dec22 125:37 nginx: worker process is shutting down
nobody 60577 0.9 0.0 47444 8040 ? D Dec22 125:33 nginx: worker process is shutting down
nobody 60578 0.9 0.0 49720 14280 ? D Dec22 127:54 nginx: worker process is shutting down
nobody 60579 0.9 0.0 47380 7896 ? D Dec22 126:20 nginx: worker process is shutting down
nobody 60580 0.9 0.0 47452 12620 ? D Dec22 127:52 nginx: worker process is shutting down
nobody 60581 0.9 0.0 46848 7856 ? D Dec22 127:09 nginx: worker process is shutting down
nobody 60582 0.9 0.0 47280 12064 ? D Dec22 126:26 nginx: worker process is shutting down
过了一会之后再查看，已经关闭好了
root@mysql243:/usr/local/nginx/sbin# ps aux|grep nginx
root 35568 0.0 0.0 30588 2980 ? S 16:30 0:00 nginx: master process /usr/local/nginx/sbin/nginx
nobody 35569 1.5 0.0 51340 22768 ? S 16:30 0:01 nginx: worker process
nobody 35570 0.7 0.0 47988 19436 ? S 16:30 0:00 nginx: worker process
nobody 35571 0.6 0.0 48288 19664 ? S 16:30 0:00 nginx: worker process
nobody 35572 0.7 0.0 48836 20368 ? S 16:30 0:00 nginx: worker process
nobody 35573 0.7 0.0 48100 19636 ? S 16:30 0:00 nginx: worker process
nobody 35574 0.6 0.0 48364 19736 ? S 16:30 0:00 nginx: worker process
nobody 35575 0.8 0.0 48564 20072 ? S 16:30 0:01 nginx: worker process
nobody 35576 1.2 0.0 49080 20536 ? S 16:30 0:01 nginx: worker process
root 36007 0.0 0.0 7640 1012 pts/12 S+ 16:32 0:00 grep --color=auto nginx
root 60574 0.0 0.0 30572 964 ? Ss Dec22 0:00 nginx: master process /usr/local/nginx/sbin/nginx
6.关闭旧版本的nginx进程
kill -QUIT `cat /usr/local/nginx/logs/nginx.pid.oldbin`
root@mysql243:/usr/local/nginx/sbin# ps aux|grep nginx
root 35568 0.0 0.0 30588 2980 ? S 16:30 0:00 nginx: master process /usr/local/nginx/sbin/nginx
nobody 35569 1.2 0.0 47964 19500 ? S 16:30 0:01 nginx: worker process
nobody 35570 0.6 0.0 47988 19436 ? S 16:30 0:01 nginx: worker process
nobody 35571 0.8 0.0 48432 19944 ? S 16:30 0:01 nginx: worker process
nobody 35572 1.0 0.0 50120 21552 ? S 16:30 0:01 nginx: worker process
nobody 35573 0.9 0.0 48408 19808 ? S 16:30 0:01 nginx: worker process
nobody 35574 0.5 0.0 48364 19736 ? S 16:30 0:00 nginx: worker process
nobody 35575 0.9 0.0 48564 20076 ? S 16:30 0:01 nginx: worker process
nobody 35576 0.9 0.0 47768 19304 ? S 16:30 0:01 nginx: worker process
root 36146 0.0 0.0 7640 1012 pts/12 S+ 16:33 0:00 grep --color=auto nginx
7.删除旧的软链接,创建新的软链
cd /usr/local
rm -f nginx
ln -s /usr/local/nginx-1.6.2 nginx
8.观察access.log 是否正常
