Hi On Mon, Apr 24, 2017 at 05:58:34PM +0200, Sékine Coulibaly wrote: > Hi, > > I'm gathering some information regarding UDP load balancing. I've come > accross this in > https://www.nginx.com/resources/admin-guide/udp-health-check/ and I'm quite > puzzled : > > "NGINX can mark the server as unavailable and stop sending UDP datagrams to > it for some time if the server replies with an error or times out. > The number of consecutive failed connection attempts within a certain time > period is set with the max_fails parameter for an upstream server (default > value is 1)." > > What is unclear to me is the "failed connection attempt" term.
Thanks for spotting this, we'll fix the documentation. This phrase obviously came from TCP. > UDP being a > connectionless protocol, it's unclear what is the actual method used by > NGINX to decide whether a passive health check is successfull or not. Would > the existence of traffic from server to Nginx be a sign of success or are > other methods involved ? A UDP session is considered unsuccessful if - a UDP socket I/O error happened, usually as a result of an ICMP error report - proxied server did not send the response within proxy_timeout if proxy_responses is set. If it's unset, this error can never happen. -- Roman Arutyunyan _______________________________________________ nginx mailing list [email protected] http://mailman.nginx.org/mailman/listinfo/nginx
