nginx实现负载均衡

参考官网：

http://nginx.org/en/docs/http/load_balancing.html

关键配置部分：

http {
    upstream myapp1 {
        server srv1.example.com;
        server srv2.example.com;
        server srv3.example.com;
    }

    server {
        listen 80;

        location / {
            proxy_pass http://myapp1;
        }
    }
}

例如：

http {
    upstream myapp1 {
        server localhost:8091;
        server localhost:8092;
    }

    server {
        listen 80;

        location / {
            proxy_pass http://myapp1;
        }
    }
}

这样，在浏览器输入http://localhost/hello，即可分发到localhost:8091/hello或localhost:8092/hello