nginx负载均衡二：配置

配置方法一（可用）：

upstream  tomcatserver1  {
    server 192.168.70.170 weight=;
    server 192.168.70.172;
    server 192.168.70.173 down;
    server 192.168.70.174;
    server 192.168.70.175 backup;
}   

 server {
        listen       ;
        server_name  localhost;
        #charset koi8-r;
        #access_log  logs/host.access.log  main;
        location / {
            proxy_pass   http://tomcatserver1

;   index index.html index.htm; } }

通过以上配置，便可以实现，在访问192.168.70.169这个网站时，由于配置了proxy_pass地址，所有请求都会先通过nginx反向代理服务器，在服务器将请求转发给目的主机时，读取upstream为 tomcatsever1的地址，读取分发策略，配置tomcat1权重为3，所以nginx会将大部分请求发送给49服务器上的tomcat1，也就是192.168.70.170；较少部分给tomcat2来实现有条件的负载均衡，当然这个条件就是服务器1、2的硬件指数处理请求能力。

1）down：表示单前的server暂时不参与负载

2）Weight：默认为1.weight越大，负载的权重就越大。

3）max_fails：允许请求失败的次数默认为1.当超过最大次数时，返回proxy_next_upstream 模块定义的错误

4）fail_timeout：max_fails 次失败后，暂停的时间。

5）Backup：其它所有的非backup机器down或者忙的时候，请求backup机器。所以这台机器压力会最轻。

配置方法二（可用）：

#user  nobody;
worker_processes  ;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/nginx.pid;

events {
    worker_connections  ;
}

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

    #log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
    #                  '$status $body_bytes_sent "$http_referer" '
    #                  '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  ;
    keepalive_timeout  ;

    #gzip  on;

　　// 位置1：upstream
    upstream  192.168.70.169  {
    　　server   192.168.70.170;
    　　server   192.168.70.172;
    　　#ip_hash;
    }

    server {
        listen       ;
        server_name  localhost;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        location / {

            root   html;
            index  index.html index.htm index.php;

        }

        #error_page                /.html;

        # redirect server error pages to the static page /50x.html
        #
        error_page        /50x.html;
        location = /50x.html {
            root   html;
        }

        # proxy the PHP scripts to Apache listening on 127.0.0.1:
        #
        #location ~ \.php$ {
        #    proxy_pass   http://127.0.0.1;
        #}

        # pass the PHP scripts to FastCGI server listening on 127.0.0.1:
        #
        location ~ \.php$ {
            root           html;
            #fastcgi_pass   127.0.0.1:;
            fastcgi_index  index.php;
       #    fastcgi_param  SCRIPT_FILENAME  /scripts$fastcgi_script_name;
            fastcgi_param  SCRIPT_FILENAME  /$document_root$fastcgi_script_name;

　　　　　　　//位置2：proxy_pass　
            proxy_pass        http://192.168.70.169;
            proxy_set_header   Host             $host;
            proxy_set_header   X-Real-IP        $remote_addr;
            proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;

            include        fastcgi_params;

        }

        # deny access to .htaccess files, if Apache's document root
        # concurs with nginx's one
        #
        #location ~ /\.ht {
        #    deny  all;
        #}
    }

    # another virtual host using mix of IP-, name-, and port-based configuration
    #
    #server {
    #    listen       ;
    #    listen       somename:;
    #    server_name  somename  alias  another.alias;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}

    # HTTPS server
    #
    #server {
    #    listen        ssl;
    #    server_name  localhost;

    #    ssl_certificate      cert.pem;
    #    ssl_certificate_key  cert.key;

    #    ssl_session_cache    shared:SSL:1m;
    #    ssl_session_timeout  5m;

    #    ssl_ciphers  HIGH:!aNULL:!MD5;
    #    ssl_prefer_server_ciphers  on;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}

}