nginx生成可预测的会话？

Question

我使用nginx和uwsgi来部署我的django 我遇到了安全问题The remote web server generates predictable session IDs.

Ports
tcp/80
Sending several requests gives us the following session IDs :

SERVERID=locationserverfarm1|Vv4q4|Vv4q4
SERVERID=locationserverfarm2|Vv4q4|Vv4q4
SERVERID=locationserverfarm3|Vv4q4|Vv4q4
SERVERID=locationserverfarm2|Vv4q4|Vv4q4
SERVERID=locationserverfarm1|Vv4q4|Vv4q4  

如何设置让它生成随机会话ID ??? 请帮我。谢谢。

这是我的nginx设置：

nginx.conf

user www-data;
worker_processes 1;
pid /run/nginx.pid;

events {
    worker_connections 3000;

}

http {

    ##
    # Basic Settings
    ##
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    # server_tokens off;

    # server_names_hash_bucket_size 64;
    # server_name_in_redirect off;

    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    ##
    # SSL Settings
    ##

    ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
    ssl_prefer_server_ciphers on;

    ##
    # Logging Settings
    ##

    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;


    ##
    # Gzip Settings
    ##

    gzip on;
    gzip_disable "msie6";

    # gzip_vary on;
    # gzip_proxied any;
    # gzip_comp_level 6;
    # gzip_buffers 16 8k;
    # gzip_http_version 1.1;
    # gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

    ##
    # Virtual Host Configs
    ##

    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;
}

myweb.conf

upstream django {

    server 127.0.0.1:8001;  
}

server {

    listen     80;
    server_name 127.0.0.1;  
    charset     utf-8;

    # max upload size
    client_max_body_size 75M;   # adjust to taste

    #security
    add_header X-Frame-Options "DENY";
    add_header X-Content-Type-Options "nosniff";
    add_header X-XSS-Protection "1; mode=block";


    location /static {

        alias /usr/share/nginx/ENV/mysite/mysite/staticfiles;  

    }

    location / {
        uwsgi_pass  django;
        include     /etc/nginx/uwsgi_params; # the uwsgi_params file you installed

    }
}