nginx 实现mysql的负载均衡

    默认Nginx只支持http的反向代理，要想nginx支持tcp的反向代理，还需要在编译时增加tcp代理模块支持，即nginx_tcp_proxy_module

下面操作步骤只让nginx支持tcp_proxy，没有加入prce、gzip、ssl等功能，如需要，可自行在编译时加上相关参数。

wget https://github.com/yaoweibin/nginx_tcp_proxy_module/archive/master.zip
unzip master
 tar -zxvf nginx-1.6.3.tar.gz 
cd nginx-1.6.3
patch -p1 < ../nginx_tcp_proxy_module-master/tcp.patch 
./configure --add-module=../nginx_tcp_proxy_module-master --prefix=/usr/local/nginx-1.6.3 --with-http_stub_status_module --with-http_gzip_static_module
make
make install

nginx.conf主配置文件中增加如下配置配置：（也可以在主配置文件中配置include,包含tcp转发的配置文件include /usr/local/nginx-1.6.3/conf/tcp_proxy.conf;）

user  nobody;
worker_processes  1;


events {
    worker_connections  1024;
}

include /usr/local/nginx-1.6.3/conf/tcp_proxy.conf;

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  0;
    keepalive_timeout  65;

    #gzip  on;

    server {
        listen       3306;
        server_name  localhost;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

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

    location /nginx_status {
        stub_status on;
            access_log  logs/nginx_status.log;
        allow 10.195.197.124;
        deny all;
    }

        #error_page  404              /404.html;

        # redirect server error pages to the static page /50x.html
        #
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }

    }

}

tcp {
    upstream mysql {
        server 10.207.238.66:3306;
        server 10.207.238.67:3306;

        check interval=3000 rise=2 fall=5 timeout=1000;
        #check interval=3000 rise=2 fall=5 timeout=1000
        #check interval=3000 rise=2 fall=5 timeout=1000
        #check_http_send "GET /HTTP/1.0\r\n\r\n";
        #check_http_expect_alive http_2xxhttp_3xx;
    }

    server {
listen 3307;
        proxy_pass mysql;
    }
}

说明：
check interval 健康检查，单位是毫秒
rise 检查几次正常后，将reslserver加入以负载列表中
fall 检查几次失败后，摘除realserver
timeout 检查超时时间，单位许毫秒
具体可查看nginx_tcp_proxy_module-master/README,很详细。