[网站架构]安装Nginx（负载均衡器）

#运行用户
user www-data;
#启动进程
worker_processes  10;
#全局错误日志及PID文件
error_log  /var/log/nginx/error.log;
pid        /var/run/nginx.pid;
#工作模式及连接数上限
events {
    worker_connections  51200;
}
#设定http服务器，利用它的反向代理功能提供负载均衡支持
http {
 #设定mime类型
 include       /etc/nginx/mime.types;
 default_type  application/octet-stream;

 #设定日志格式
 log_format main '$remote_addr - $remote_user [$time_local] '
   '"$request" $status $bytes_sent '
   '"$http_referer" "$http_user_agent" '
   '"$gzip_ratio"';
 log_format download '$remote_addr - $remote_user [$time_local] '
   '"$request" $status $bytes_sent '
   '"$http_referer" "$http_user_agent" '
   '"$http_range" "$sent_http_content_range"';

 #设定请求缓冲
        client_header_buffer_size    1k;
        large_client_header_buffers  4 4k;
        #开启gzip模块
        gzip on;
        gzip_min_length  1100;
        gzip_buffers     4 8k;
        gzip_types       text/plain;
        output_buffers   1 32k;
        postpone_output  1460;

 #设定access log
 #access_log /var/log/nginx/access.log;
        client_header_timeout  3m;
        client_body_timeout    3m;
        send_timeout           3m;
        sendfile                on;
        tcp_nopush              on;
        tcp_nodelay             on;
        keepalive_timeout  65;
        #设定负载均衡的服务器列表
        upstream mysvr {
  #weigth参数表示权值，权值越高被分配到的几率越大
  #本机上的Squid开启3128端口
                server 192.168.1.12:3128 weight=1;
                server 192.168.1.34:80   weight=3;
                #server 192.168.1.56:80   weight=5;
        }
        #设定虚拟主机
        server {
                listen          80;
                server_name   www.test.com .test.com;
                #charset gb2312;
                #设定本虚拟主机的访问日志
                #access_log  logs/www.yejr.com.access.log  main;
  #如果访问 /img/*, /js/*, /css/* 资源，则直接取本地文件，不通过squid
  #如果这些文件较多，不推荐这种方式，因为通过squid的缓存效果更好
                location ~ ^/(img|js|css)/  {
                        root    /var/www;
                        expires 24h;
                }
                #对 "/" 启用负载均衡　
                location / {
                        proxy_pass     http://mysvr;
                        proxy_redirect          off;
                        proxy_set_header        Host $host;
                        proxy_set_header        X-Real-IP $remote_addr;
                        proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
                        client_max_body_size    10m;
                        client_body_buffer_size 128k;
                        proxy_connect_timeout   90;
                        proxy_send_timeout      90;
                        proxy_read_timeout      90;
                        proxy_buffer_size       4k;
                        proxy_buffers           4 32k;
                        proxy_busy_buffers_size 64k;
                        proxy_temp_file_write_size 64k;
                }
                #设定查看Nginx状态的地址
                location /Nginx {
                        stub_status             on;
                        #access_log              on;
                        auth_basic              "Nginx状态信息(QQ:5145454)";
                        auth_basic_user_file /etc/nginx/conf/.htpasswd;
                }
        }
}