End-to-end disconnect notification?

Hi, given
client --(tcp)–>nginx --(fcgi)–>fcgi server --(tcp)–> back-end server
if the client initiates a TCP disconnect, is there a way for NGINX to
out the termination to the fcgi server?
Or if the back-end server disconnects, how can the fcgi server
the disconnect all the way to nginx and the client?

From what I observed, a client could send a TCP FIN, but NGINX will keep
FCGX connection up.
Thank you.

Posted at Nginx Forum: