socketio 握手前中断报错

location / {
proxy_pass http://127.0.0.1:9999; proxy_connect_timeout 60;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-NginX-Proxy true;

# 下面是关键
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
# 这是配置webpysessoin丢失的问题
fastcgi_param  SCRIPT_NAME        "";
}