nginx做负载均衡反向代理的配置

nginx.conf配置文件内容:

#根据服务器核心数设定
worker_processes  1;
error_log    /usr/local/nginx/logs/nginx_error.log    crit;
pid          /usr/local/nginx/nginx.pid;
worker_rlimit_nofile   51200;
events {
     use epoll;
     worker_connections 51200;
}
http {
    include            mime.types;
    default_type    application/octet-stream;
    source_charset GB2312;
    server_names_hash_bucket_size 256;
    client_header_buffer_size 256k;
    large_client_header_buffers 4 256k;
    #size limits
    client_max_body_size            50m;
    client_body_buffer_size        256k;
    client_header_timeout    3m;
    client_body_timeout 3m;
    send_timeout            3m;
    sendfile on;
    tcp_nopush        on;
    keepalive_timeout 120; #参数加大,以解决做代理时502错误
    tcp_nodelay on;

    #定义一个服务器列表,weight代表权重,值越高越容易分配到.
    upstream webservers{
        server 192.168.12.2:80 weight=1;
        server 192.168.12.3:80 weight=2;
        #nginx支持的几种算法,1,轮询 2,weight 3,ip hash 4,fair(第三方) 5,url_hash (第三方)
        #ip_hash为每个请求按访问ip的hash结果分配，每个访客有固定的后端服务器，可以解决session问题
        ip_hash;
    }
    server {
        listen                80;
        server_name  192.168.12.1;
        charset GB2312;
        location / { 
        #使用proxy_pass代替一般配置中的fastcgi_pass
        proxy_pass         
        proxy_redirect off ;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header REMOTE-HOST $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        client_max_body_size 50m;
        client_body_buffer_size 256k;
        proxy_connect_timeout 30;
        proxy_send_timeout 30;
        proxy_read_timeout 60;
        proxy_buffer_size 256k;
        proxy_buffers 4 256k;
        proxy_busy_buffers_size 256k;
        proxy_temp_file_write_size 256k;
        proxy_next_upstream error timeout invalid_header http_500 http_503 http_404;
        proxy_max_temp_file_size 128m; 
        }
    }
}