NGINX:反向代理负载均衡

nginx.conf配置文件：
user  nobody nobody;
worker_processes  4;
error_log  logs/error.log crit;
pid        logs/nginx.pid;
worker_rlimit_nofile 65535;
events {
    use epoll;
    worker_connections  65535;
}
http {
    server_tokens off;
    include       mime.types;
    default_type  application/octet-stream;
    server_names_hash_bucket_size 128;
 
    sendfile        on;
    tcp_nopush      on;
    tcp_nodelay     on;
    keepalive_timeout  65;
    gzip  on;
    gzip_min_length 1k;
    gzip_buffers  4 16k;
    gzip_http_version 1.0;
    gzip_comp_level 2;
    gzip_types text/plain application/x-javascript text/css  application/xml;
    gzip_vary on;

    upstream mysrv {
        server 192.168.1.1:80 weight=1 max_fails=2 fail_timeout=30s;
        server 192.168.1.2:80 weight=1 max_fails=2 fail_timeout=30s;
    }
    upstream bench {
        server 192.168.1.3:80 weight=1 max_fails=2 fail_timeout=30s;
        server 192.168.1.4:80 weight=1 max_fails=2 fail_timeout=30s;
    }
    upstream bbs {
        server 192.168.1.5:80 weight=1 max_fails=2 fail_timeout=30s;
        server 192.168.1.6:80 weight=1 max_fails=2 fail_timeout=30s;
    }

    include vhost/*.conf;
}

aaa_example_com.conf配置文件：
server {
        listen       80;
        server_name  aaa.example.com;
        index index.php index.html index.htm index.shtml;

        log_format proxy '$remote_addr| $upstream_addr| $connection| $upstream_status| $time_local| $request|'
                        ' $status|  $body_bytes_sent|  $bytes_sent|  $http_referer|'
                        ' $http_user_agent| $upstream_response_time| $msec| $request_time';
        access_log logs/aaa_access.log proxy;

        location / {
                proxy_pass http://mysrv;
                include proxy.conf;
                }
       
        location /bench/ {
                proxy_pass http://bench;
                include proxy.conf;
                }
}

bbs_example_com.conf配置文件：
server {
        listen       80;
        server_name  bbs.example.com *.bbs.example.com;

        log_format proxy '$remote_addr| $upstream_addr| $connection| $upstream_status| $time_local| $request|'
                        ' $status|  $body_bytes_sent|  $bytes_sent|  $http_referer|'
                        ' $http_user_agent| $upstream_response_time| $msec| $request_time';
        access_log logs/bbs_access.log proxy;

        location / {
                proxy_pass http://bbs;
                include proxy.conf;
                }

}

proxy.conf配置文件：
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 50m;   //允许客户端请求的最大单个文件字节数
client_body_buffer_size 256k;  //缓冲区代理缓冲客户端请求的最大字节数
proxy_connect_timeout 30;   //连接后端服务器超时时间
proxy_send_timeout 30;   //后端服务器发送数据超时时间
proxy_read_timeout 60;   //后端服务器响应请求超时时间
proxy_buffer_size 4k;    //代理请求缓存区大小
proxy_buffers 4 32k;
proxy_busy_buffers_size 64k;   //系统繁忙时可申请的proxy_buffers大小
proxy_temp_file_write_size 64k;  //proxy缓存临时文件的大小
proxy_next_upstream error timeout invalid_header http_500 http_503 http_404;   //故障转移
proxy_max_temp_file_size 128m; 

proxy_set_header指令用于在向反向代理的后端web服务器发起请求时添加指定Header头信息，当后端web服务器上有多个基于域名的虚拟主机时，要通过添加Header头信息Host，来指定请求的域名，这样后端web服务器才能识别该反向代理访问请求由哪个虚拟主机来处理。