nginx负载均衡-基于多域名的负载均衡（二）

注意：

(1) 做负载均衡技术至少需要三台服务器：一台独立的负载均衡器，两台web服务器做集群

(2) keeplived（高可用）+nginx（负载均衡）可以实现多域名对应一个VIP,并且访问不同域名，显示不同主页，可行，已测

一、nginx分别代理后端web1 和 web2的三台虚拟主机

1、web1（nginx-10.0.0.7）配置基于域名的虚拟主机（以下配置了3个虚拟主机）

[root@Oldboy extra]# cat www.conf 
server {
        listen        80;
        server_name  www.etiantian.org;
        location / {
            root   html/www;              #这个地方指向nginx安装目录的html/www/目录下
            index  index.html index.htm;
        }
}
[root@Oldboy extra]# cat bbs.conf 
server {
        listen        80;
        server_name  bbs.etiantian.org; 
        location / {
            root   html/bbs;
            index  index.php  index.html index.htm;
        }
}
[root@Oldboy extra]# cat blog.conf 
server {
        listen        80;
        server_name  blog.etiantian.org;
        location / {
        root     html/blog;
        index    index.php;
}

        location ~ .*\.(php|php5)?$ {
        root html/blog;
        fastcgi_pass  127.0.0.1:9000;
        fastcgi_index index.php;
        include fastcgi.conf;
        }
}

2、web2（apache-10.0.0.8）配置基于域名的虚拟主机（以下配置了3个虚拟主机）

[root@Oldboy extra]# egrep -v "#|^$" httpd-vhosts.conf 

NameVirtualHost *:80
<VirtualHost *:80>
    ServerAdmin oldboy@oldboyedu.com
    DocumentRoot "/application/apache2.2.31/htdocs/www"
    ServerName   www.etiantian.org
    ServerAlias etiantian.org
    ErrorLog "/app/logs/www-error_log"
    CustomLog "/app/logs/www-access_log" common
</VirtualHost>
<VirtualHost *:80>
    ServerAdmin oldboy@oldboyedu.com
    DocumentRoot "/application/apache2.2.31/htdocs/bbs"
    ServerName   bbs.etiantian.org
    ErrorLog "/app/logs/bbs-error_log"
    CustomLog "/app/logs/bbs-access_log" common
</VirtualHost>
<VirtualHost *:80>
    ServerAdmin oldboy@oldboyedu.com
    DocumentRoot "/application/apache2.2.31/htdocs/blog"
    ServerName   blog.etiantian.org
    ErrorLog "/app/logs/blog-error_log"
    CustomLog "/app/logs/blog-access_log" common
</VirtualHost>

3、负载均衡器（LB-nginx-10.0.0.6）配置反向代理

[root@Oldboy conf]# cat nginx.conf
worker_processes  1;
events {
    worker_connections  1024;
}
http {
    include       mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65;

 upstream web_pool ｛                                             地址池
    server 10.0.0.7:80  weight=1;
    server 10.0.0.8:80  weight=1;
}




server {
        listen       80;
        server_name  www.etiantian.org  bbs.etiantian.org  blog.etiantian.org;

        #ssl on;
    #ssl_certificate /usr/local/nginx/conf/33iq.crt;
    #ssl_certificate_key /usr/local/nginx/conf/33iq_nopass.key;

        location / {
            index  index.html index.htm;
            proxy_pass http://web_pool;                                                   反向代理到地址池
            proxy_set_header Host  $host;                                                将请求头信息也一起反代给后端的服务器
            proxy_set_header X-Forwarded-For $remote_addr;               将客户端的真实ip映射到后端的web服务器中
        }
    }


}

解释：
当客户端分别访问 www.etiantian.org 、 bbs.etiantian.org、 blog.etiantian.org 时，nginx会带着这些主机头请求后端web集群，web服务器中的虚拟主机会自动识别nginx请求的主机头，并回复nginx请求，nginx再将web端的回复，交给客户端。

也可以代理单台服务器：
location / {
            index  index.html index.htm;
            proxy_pass http://172.16.100.100;                                                   
            proxy_set_header Host  $host;                                                
            proxy_set_header X-Forwarded-For $remote_addr;           
        }

4、修改web端日志访问ip

默认情况下web端日志记录的访问ip是负载均衡器的ip，所以需要修改为真实客户端ip
(1) 负载均衡器（LB）配置
server {
        listen       80;
        server_name  blog.etiantian.org;
        location / {
            index  index.html index.htm;
            proxy_pass http://blog_pool;                                          代理blog动态页面
            proxy_set_header Host  $host;
            proxy_set_header X-Forwarded-For $remote_addr;      负载均衡器开启ip转发，将客户端ip映射到web服务器
        }
    }
(2) web1端修改日志格式来接收客户端的真实ip（nginx主配置文件）
cat  nginx.conf

log_format  main  '$http_x_forwarded_for  $remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent"';
(3) web2端修改日志格式来接收客户端的真实ip （apache主配置文件）
LogFormat "%{X-Forwarded-For}i %h %l %u %t \"%r\" %>s %b"  common