I've NGINX 1.12-1 running on CentOS 7.2 and being used for DNS load balancing. However I'm seeing lots of errors in the "dns.log".. I've no access to the system right now but error was like.. "No response received from the upstream server" The occurrence of the errors is no continuous but it's pretty frequent.
The three backend servers are Windows 2012 R2 DNS servers
I will provide the nginx.conf details soon.
I may have to do some tuning besides upgrade to an appropriate version I guess. Can anyone help to suggest/recommend tuning to minimize the errors or rather not to have them at all?