id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
1511	multiple resolver would retry others when someone fails	crasyangel.lhy@…	Ruslan Ermilov	"As mdounin mentioned, the resolver_timeout directive controls hard limit on the total DNS resolution time. If not answered, DNS queries are resent (to a different server if configured) each 5 seconds, see here:[https://trac.nginx.org/nginx/browser/nginx/src/core/ngx_resolver.c#L197]. There is no way to configure this timeout though, as this doesn't seem to be needed in most cases in practice.

To make sure DNS queries are resent to a different server if one the configured servers is down, consider using resolver_timeout set to something like 6s or more.

I set resolver_timeout to 10s, but when ngx_resolver_send_query fails, resolver do not retry, see here:[https://trac.nginx.org/nginx/browser/nginx/src/core/ngx_resolver.c#L855], the code goto failed, return ERROR and clean events
"	defect	closed	minor		other	1.13.x	fixed			2.6.32	nginx version: nginx/1.12.2 built by gcc 4.8.2 (GCC) built with OpenSSL 1.0.2h 3 May 2016 TLS SNI support enabled