On 10/02/2015 10:22 a.m., Mirza Dedic wrote: > I have users getting quite frequently this error in Squid.. > > Unable to determine IP address from hostname. > "The DNS server returned no DNS records" Means exactly what it says. > > I have in my squid.conf setup.. > > dns_nameservers 8.8.8.8 8.8.4.4 > dns_timeout 5 second > > It seems random, but 5 seconds should be enough and we're resolving against > Google public DNS servers. > > The sites it is unable to resolve are up (expedia.com, and other sites that > usually don't go down). > > Is there anything else I can do? Expedia is hosted on Akamai. Akamai load balance their CDN by doing DNS response tricks. I'm seen a few different types of failure resulting from that. - in Expedias case the DNS TTL is 12 seconds and there are two layers of CNAME to resolve before one gets to an IP. Those CNAMEs themselves only have TTL of a few minutes. The Akamai behaviour that could result in that no-IPs error is when only CNAME results are returned. Squid relies on the resolver to do the recursion. Sometimes all Squid gets is a bunch of nested CNAME with no IP to connect to. This is particularly bad with IPv6 lookups when the Akamai client is not v6-enabled (expedia is one such). Your Squid version can also impact results. 3.1 originally did two sequential lookups, for AAAA and A records. That was changed to parallel in 3.3, but still the longer of the two must fit within the timeout. Amos _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users
