根据 cookie 做负载均衡，$cookie_jsessionid 表示根据 cookie 中的 jsessionid 字段 做负载均衡。

worker_processes  1;

events {
    worker_connections  1024;
}

http {
    include       mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65;

    upstream httpds {
        # 开启 cookie 负载均衡
        hash $cookie_jsessionid;
        server 192.168.44.102;
        server 192.168.44.103;
    }

    server {
        listen       80;
        server_name  www.rainx.top;

        location / {
            proxy_pass http://httpds;
        }

        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
}