只需2步配置Nginx服务器集群

1，在主服务器192.168.0.162上配置upstream 也就是服务器组，（在http作用域下配置）

upstream imageserver {
     server 192.168.0.163:80 weight=1 max_fails=2 fail_timeout=30s;
     server 192.168.0.137:80 weight=1 max_fails=2 fail_timeout=30s; 
}

imageserver：服务器组名称

weight：权重

max_fails：最大失连次数 超过这个次数后就过一段时间再次重连

fail_timeout：失连时间限制 超过这个时间就算一次失连

 

2，在主服务器192.168.0.162上配置下游调用（在server作用域下配置）

location ~ \.(jpg|jpeg|png|gif)$ {     
    proxy_set_header X-Forwarded-For $remote_addr;#将真实客户端ip发送到要请求的服务器 
    proxy_pass http://imageserver; #代理服务器配置为第一步里面的服务器组 imageserver 
}

3，确保在192.168.0.163和192.168.0.137两台机子上都有相同的资源

4，在主服务器192.168.0.162上新建一个index.html

当访问index.html时，nginx会从配置的服务器组中根据权重选择请求其中一个服务器上的logo.jpg。为了显示效果，可以在192.168.0.163和192.168.0.137两台机器上放上两个不同的图片，都命名为logo.jpg，然后刷新index.html观察图片变化。

5，完整配置如下：

user  www www;

worker_processes auto;
worker_cpu_affinity auto;

error_log  /home/wwwlogs/nginx_error.log  crit;

pid        /usr/local/nginx/logs/nginx.pid;

#Specifies the value for maximum file descriptors that can be opened by this process.
worker_rlimit_nofile 51200;

events
    {
        use epoll;
        worker_connections 51200;
        multi_accept off;
        accept_mutex off;
    }

http
    {
        include       mime.types;
        default_type  application/octet-stream;

        server_names_hash_bucket_size 128;
        client_header_buffer_size 32k;
        large_client_header_buffers 4 32k;
        client_max_body_size 50m;

        sendfile on;
        sendfile_max_chunk 512k;
        tcp_nopush on;

        keepalive_timeout 60;

        tcp_nodelay on;

        fastcgi_connect_timeout 300;
        fastcgi_send_timeout 300;
        fastcgi_read_timeout 300;
        fastcgi_buffer_size 64k;
        fastcgi_buffers 4 64k;
        fastcgi_busy_buffers_size 128k;
        fastcgi_temp_file_write_size 256k;

        gzip on;
        gzip_min_length  1k;
        gzip_buffers     4 16k;
        gzip_http_version 1.1;
        gzip_comp_level 2;
        gzip_types     text/plain application/javascript application/x-javascript text/javascript text/css application/xml application/xml+rss;
        gzip_vary on;
        gzip_proxied   expired no-cache no-store private auth;
        gzip_disable   "MSIE [1-6]\.";

        #limit_conn_zone $binary_remote_addr zone=perip:10m;
        ##If enable limit_conn_zone,add "limit_conn perip 10;" to server section.

        server_tokens off;
        access_log on;
		upstream imageserver {
			 server 192.168.0.163:80 weight=1 max_fails=2 fail_timeout=30s;
			 server 192.168.0.137:80 weight=1 max_fails=2 fail_timeout=30s;
		}		
server
    {
        listen 80 default_server;
        #listen [::]:80 default_server ipv6only=on;
        server_name _;
        index index.html index.htm index.php;
        root  /home/wwwroot/default;

        #error_page   404   /404.html;

        # Deny access to PHP files in specific directory
        #location ~ /(wp-content|uploads|wp-includes|images)/.*\.php$ { deny all; }

        include enable-php-pathinfo.conf;

        location /nginx_status
        {
            stub_status on;
            access_log   on;
        }

        location ~ \.(gif|jpg|jpeg|png|bmp|swf)$
        {         
		  proxy_pass http://imageserver;
		  proxy_set_header X-Forwarded-For $remote_addr;
        }

        location ~ .*\.(js|css)?$
        {
            expires      12h;
        }

        location ~ /.well-known {
            allow all;
        }

        location ~ /\.
        {
            deny all;
        }

        access_log  /home/wwwlogs/access.log;
    }
	include vhost/*.conf;
}