安装

下载地址: http://nginx.org/download/nginx-1.4.2.tar.gz
安装准备: nginx依赖于pcre库,要先安装pcre

yum install pcre pcre-devel
cd /usr/local/src/
wget http://nginx.org/download/nginx-1.4.2.tar.gz
tar zxvf nginx-1.4.2.tar.gz 
cd nginx-1.4.2
./configure --prefix=/usr/local/nginx
make && make install

启动:

cd /ulsr/local/nginx, 看到如下4个目录
./
 ....conf 配置文件  
 ... html 网页文件
 ...logs  日志文件 
 ...sbin  主要二进制程序

[root@localhost nginx]# ./sbin/nginx 
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
....
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] still could not bind()

不能绑定80端口,80端口已经被占用
(有时是自己装了apache,nginx等,还有更多情况是操作系统自带了apache并作为服务启动)
解决: 把占用80端口的软件或服务关闭即可。

信号控制

信号	描述
TERM, INT	Quick shutdown
QUIT	Graceful shutdown 优雅的关闭进程,即等请求结束后再关闭
HUP	Configuration reload ,Start the new worker processes with a new configuration Gracefully shutdown the old worker processes 改变配置文件,平滑的重读配置文件
USR1	Reopen the log files 重读日志,在日志按月/日分割时有用
USR2	Upgrade Executable on the fly 平滑的升级
WINCH	Gracefully shutdown the worker processes 优雅关闭旧的进程(配合USR2来进行升级)

注意：nginx进程可能有多个，一个master进程，其余的都是worker进程

• 关闭进程

kill -INT master进程的id

root@uchao:/usr/local/nginx# ps aux|grep nginx
root       2278  0.0  0.0  22404   372 ?        Ss   14:28   0:00 nginx: master process ./sbin/nginx
nobody     2279  0.0  0.2  22804  2276 ?        S    14:28   0:00 nginx: worker process
root       2284  0.0  0.2  16536  2148 pts/9    S+   14:29   0:00 grep --color=auto nginx
root@uchao:/usr/local/nginx# kill -INT 2278
root@uchao:/usr/local/nginx# ps aux|grep nginx
root       2317  0.0  0.2  16536  2208 pts/9    S+   14:55   0:00 grep --color=auto nginx
root@uchao:/usr/local/nginx# 

• 优雅的关闭进程,即等请求结束后再关闭

kill -QUIT master进程的id

• 重读配置文件
  改变配置文件,平滑的重读配置文件，首先会根据新的配置文件启动新的worker进程，等待老的请求结束后，再结束老的worker进程

kill -HUP master进程的id

• 重读日志文件
  在linux上文件的标识是inode，nginx向日志文件写日志也是识别inode，就算你修改日志文件的文件名称，日志还是向修改后的文件继续写，所以如果要把原来的日志文件备份，让日志写到新的文件上，光修改原来的日志文件名，再创建新的日志文件是不够的，此时还需要向mater进程发送USR1信号。

kill -USR1 master进程的id

• 不用每次都查询进程id

kill -HUP `cat logs/nginx.pid`

命令

root@uchao:/usr/local/nginx# ./sbin/nginx -h
nginx version: nginx/1.4.2
Usage: nginx [-?hvVtq] [-s signal] [-c filename] [-p prefix] [-g directives]

Options:
  -?,-h         : this help
  -v            : show version and exit
  -V            : show version and configure options then exit
  -t            : test configuration and exit
  -q            : suppress non-error messages during configuration testing
  -s signal     : send signal to a master process: stop, quit, reopen, reload
  -p prefix     : set prefix path (default: /usr/local/nginx/)
  -c filename   : set configuration file (default: conf/nginx.conf)
  -g directives : set global directives out of configuration file

root@uchao:/usr/local/nginx# ./sbin/nginx -s reload
root@uchao:/usr/local/nginx# ./sbin/nginx -s stop
root@uchao:/usr/local/nginx# ps aux|grep nginx     
root       2460  0.0  0.2  16536  2196 pts/9    S+   16:27   0:00 grep --color=auto nginx
root@uchao:/usr/local/nginx# 

• 命令和信号的对应关系
  ./sbin/nginx -s reload ———》kill -HUP `cat logs/nginx.pid`
  ./sbin/nginx -s stop ———》kill -INT `cat logs/nginx.pid`
  ./sbin/nginx -s reopen ———》kill -USR1 `cat logs/nginx.pid`
  ./sbin/nginx -s quit ———》kill -QUIT `cat logs/nginx.pid`

• 检测配置文件是否有问题

root@uchao:/usr/local/nginx# ./sbin/nginx -t
nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/nginx/conf/nginx.conf test is successful