Hi,
I need to enable tcp keepalive messages betwin nginx and backend. There is POST which have to be replyed from backend within about 40-50 minutes but my session closed by timeout(2 hour), i think it is firewall wich drop session from nginx to backend due unactivity. If I make a curl directly to backend from nginx server, there are tcp keepalive in tcpdump and I receive reply from backend in 40 minutes. Tried to use proxy_socket_keepalive=on in location section but tcpkeepalive not appear in tcpdump and session stil close by timeout. So what is the proper way to enable proxy_socket_keepalive?