Increased DNS failure rate when using ServerDNSResolvConfFile with tor 0.3.4.9 (as opposed to 0.3.3.x)
A major tor exit relay operator reports that after upgrading from 0.3.3.x to 0.3.4.9 his DNS failure rate significantly increased.
He also reported that he is observing DNS issues only when using ServerDNSResolvConfFile and no problems when not using that config option. Using that option worked fine on tor 0.3.3.x
With ServerDNSResolvConfFile option on 0.3.4.9:
Dec 13 02:39:52.000 [notice] eventdns: Nameserver 188.8.131.52:53 is back up Dec 13 02:39:53.000 [warn] eventdns: All nameservers have failed