今天讲讲怎样实现UDP的反向代理，Nginx从1.9.13起开始发布ngx_stream_core_module模块不仅能支持TCP代
安装Nginx并启用模块
ngx_stream_core_module这个模块并不会默认启用，需要在编译时通过指定--with-stream参数来激活
- 编译安装
$ yum -y install proc* openssl* pcre*
$ wget http://nginx.org/download/nginx-1.15.10.tar.gz
$ tar zxvf nginx-1.15.10.tar.gz
$ cd nginx-1.15.10
$ ./configure --prefix=/usr/local/nginx --sbin-path=/usr/sbin/nginx --conf-path=/usr/local/nginx/conf/nginx.conf --error-log-path=/data/wwwlogs/nginx/error.log --http-log-path=/data/wwwlogs/nginx/access.log --pid-path=/var/run/nginx.pid --lock-path=/var/run/nginx.lock --http-client-body-temp-path=/var/cache/nginx/client_temp --http-proxy-temp-path=/var/cache/nginx/proxy_temp --http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp --http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp --http-scgi-temp-path=/var/cache/nginx/scgi_temp --user=nginx --group=nginx --with-http_ssl_module --with-http_realip_module --with-http_addition_module --with-http_sub_module --with-http_dav_module --with-http_flv_module --with-http_mp4_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_random_index_module --with-http_secure_link_module --with-http_stub_status_module --with-http_auth_request_module --with-threads --with-stream --with-stream_ssl_module --with-mail --with-mail_ssl_module --with-file-aio --with-ipv6 --with-http_spdy_module --with-cc-opt='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic'
$ make
$ make install- 配置stream模块
UDP负载均衡解决了两个关键点：高可用性和横向扩展。UDP设计是不保证端至端传送
实例：负载均衡DNS
stream模块必需在nginx.conf中配置
$ vim /usr/local/nginx/conf/nginx.conf
worker_processes auto;
error_log /data/wwwlogs/nginx_error.log info;
events {
worker_connections 1024;
}
stream {
upstream dns {
server 192.168.0.1:53;
server dns.example.com:53;
}
server {
listen 127.0.0.1:53 udp;
proxy_responses 1;
proxy_timeout 20s;
proxy_pass dns;
}
}