说明：
Nginx负载均衡服务器：
系统：CentOS 5.5
IP：10.15.72.73
Web服务器列表：
Web1:10.15.72.177
Web2:10.15.72.74
实现目的：
用户访问10.15.72.73服务器时，通过Nginx负载均衡到Web1和Web2服务器
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下面配置Nginx负载均衡服务器
准备篇：
一、配置好IP、DNS 、网关，确保使用远程连接工具能够连接服务器
二、配置防火墙，开启80端口
vi /etc/sysconfig/iptables #编辑防火墙配置文件,添加以下内容
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
特别提示：很多网友把这两条规则添加到防火墙配置的最后一行，导致防火墙启动失败，正确的应该是添加到默认的22端口这条规则的下面
添加好之后防火墙规则如下所示：
#####################################################################
# Firewall configuration written by system-config-securitylevel
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp --icmp-type any -j ACCEPT
-A RH-Firewall-1-INPUT -p 50 -j ACCEPT
-A RH-Firewall-1-INPUT -p 51 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp --dport 5353 -d 224.0.0.251 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m tcp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
COMMIT
#####################################################################
/etc/init.d/iptables restart#最后重启防火墙使配置生效
三、关闭SELINUX
vi /etc/selinux/config #编辑配置文件
#SELINUX=enforcing#注释掉
#SELINUXTYPE=targeted#注释掉
SELINUX=disabled#增加
:wq#保存
shutdown -r now#重启系统
四 、系统约定
软件源代码包存放位置：/usr/local/src
源码包编译安装位置：/usr/local/软件名字
五、下载软件包
1、下载nginx（目前稳定版）
2、下载pcre （支持nginx伪静态）
ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-8.30.tar.gz
3、下载ngx_cache_purge（清除指定URL缓存，方便以后扩展配置nginx缓存服务器）
六、安装编译工具及库文件（使用CentOS yum命令安装，安装的包比较多，方便以后配置lnmp环境）
yum install make apr* autoconf automake curl curl-devel gcc gcc-c++ zlib-devel openssl openssl-devel pcre-devel gd kernel keyutils patch perl kernel-headers compat* cpp glibc libgomp libstdc++-devel keyutils-libs-devel libsepol-devel libselinux-devel krb5-devel zlib-devel libXpm* freetype libjpeg* libpng* php-common php-gd ncurses* libtool* libxml2 libxml2-devel patch
安装篇
以下是用putty工具远程登录到服务器，在命令行下面操作的
安装 nginx
groupadd www #添加www组
useradd -g www www -s /bin/false #创建nginx运行账户www并加入到www组，不允许www用户直接登录系统cd /usr/local/src #进入安装目录
tar zxvf ngx_cache_purge-1.5.tar.gz #解压
tar zxvf nginx-1.0.15.tar.gz #解压
cd nginx-1.0.15
./configure --prefix=/usr/local/nginx --without-http_memcached_module
--user=www --user=www --group=www --with-http_stub_status_module --with-openssl=/usr/ --with-pcre=/usr/local/src/pcre-8.30 --add-module=../ngx_cache_purge-1.5 #配置
注意:--with-pcre=/usr/local/src/pcre-8.30指向的是源码包解压的路径，而不是安装的路径，否则会报错
make #编译
make install#安装
/usr/local/nginx/sbin/nginx #启动Nginx
=======================================================
设置nginx开启启动
vi /etc/rc.d/init.d/nginx #编辑启动文件添加下面内容
#!/bin/bash
# nginx Startup script for the Nginx HTTP Server
# it is v.0.0.2 version.
# chkconfig: - 85 15
# description: Nginx is a high-performance web and proxy server.
# It has a lot of features, but it's not for everyone.
# processname: nginx
# pidfile: /var/run/nginx.pid
# config: /usr/local/nginx/conf/nginx.conf
nginxd=/usr/local/nginx/sbin/nginx
nginx_config=/usr/local/nginx/conf/nginx.conf
nginx_pid=/usr/local/nginx/logs/nginx.pid
RETVAL=0
prog="nginx"
# Source function library.
. /etc/rc.d/init.d/functions
# Source networking configuration.
. /etc/sysconfig/network
# Check that networking is up.
[ ${NETWORKING} = "no" ] && exit 0
[ -x $nginxd ] || exit 0
# Start nginx daemons functions.
start() {
if [ -e $nginx_pid ];then
echo "nginx already running...."
exit 1
fi
echo -n $"Starting $prog: "
daemon $nginxd -c ${nginx_config}
RETVAL=$?
echo
[ $RETVAL = 0 ] && touch /var/lock/subsys/nginx
return $RETVAL
}
# Stop nginx daemons functions.
stop() {
echo -n $"Stopping $prog: "
killproc $nginxd
RETVAL=$?
echo
[ $RETVAL = 0 ] && rm -f /var/lock/subsys/nginx /usr/local/nginx/logs/nginx.pid
}
reload() {
echo -n $"Reloading $prog: "
#kill -HUP `cat ${nginx_pid}`
killproc $nginxd -HUP
RETVAL=$?
echo
}
# See how we were called.
case "$1" in
start)
start
;;
stop)
stop
;;
reload)
reload
;;
restart)
stop
start
;;
status)
status $prog
RETVAL=$?
;;
*)
echo $"Usage: $prog {start|stop|restart|reload|status|help}"
exit 1
esac
exit $RETVAL
=======================================================
:wq!#保存退出
chmod 775 /etc/rc.d/init.d/nginx #赋予文件执行权限
chkconfig nginx on #设置开机启动
/etc/rc.d/init.d/nginx restart#重启Nginx
=======================================================
