官方参考文档：http://nginx.org/en/docs/stream/ngx_stream_core_module.html
只有nginx1.9以上的版本才支持tcp负载均衡
配置必须出现在main段，不能配置在http,event和server标签段

（1）安装官方nginx

1.配置官方yum源

#vim /etc/yum.repos.d/nginx.repo 
[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/mainline/centos/7/$basearch/
gpgcheck=0
enabled=1

yum makecache
yum repolist 

2.安装nginx

yum install nginx -y 
systemctl start nginx 
systemctl enable nginx 

（2）配置tcp负载均衡

#vim /etc/nginx/nginx.conf 
stream {
        upstream ssh_proxy {
                hash $remote_addr consistent;                               //一致性hash
                server 192.9.191.31:22 max_fails=2 fail_timeout=2s;         //健康状态检测
                server 192.9.191.32:22 max_fails=2 fail_timeout=2s;
                }
        server {
                listen 2222;
                proxy_connect_timeout 1s;                       //连接超时
                proxy_timeout 20s;                              //连接超时时间，如果不配置，永远不超时
                proxy_pass ssh_proxy;       
                }
}
#systemctl reload nginx 

nginx基于tcp负载均衡

原文：https://www.cnblogs.com/lovelinux199075/p/9062219.html