Hi Theo, What happens if you set go_direct=false in your parent.config line. If it is true, it is allowed to go directly to the origin and will do a OS DNS lookup in HttpTransact if the parent search result is direct.
John On 12/12/18, 1:33 PM, "Theo Hoogerheide" <[email protected]> wrote: Hi John, Thanks for your reply. I have done some testing. When I adjust remap.conf to remap the URL’s to a destination not configured in the parent.config, I receive a 'HTTP/1.1 502 Next Hop Connection Failed’, and no DNS-queries are seen on the wire. Disabling proxy.config.http.no_dns_just_forward_to_parent, with the adjusted remap.config entires, does show the adjusted DNS-entries. So it seems the stuff in parent.config (dest_host) like you mentioned is responsible for the DNS query. This behaviour definitely changed, since 5.x and at leat up to version 6.2 the configuration I emailed earlier works without any DNS lookup. We use the parent.config to load-balance between different origins and I do not see any other way to configure this in ATS. If this is the intended behaviour, how can I then remap a url, and select a parent that needs to be used, without doing any DNS lookups? -- Kind regards, Theo Hoogerheide Lead Infrastructure Architect > On 12 Dec 2018, at 01:26, John Rushford <[email protected]> wrote: > > Hi Theo, > > I don’t see that ATS is doing DNS lookups on the parents. Your showing that ATS is doing DNS lookups on > the remapped origin hostname, aka dest_host. I think that it has always done so and the origin hostname should be resolvable > > John > >> On Dec 11, 2018, at 10:23 AM, Theo Hoogerheide <[email protected]> wrote: >> >> Hello List, >> >> I’m having difficulties to configure ATS to *not* do any DNS lookups for parents. >> >> Relevant configuration: >> >> ** records.conf: >> CONFIG proxy.config.http.parent_proxy_routing_enable INT 1 >> CONFIG proxy.config.admin.user_id STRING trafficserver >> CONFIG proxy.config.http.no_dns_just_forward_to_parent INT 1 >> >> ** parent.conf >> dest_host=liveshieldgroup001 method=GET parent=“1.1.1.1:80;" round_robin=consistent_hash qstring=ignore >> dest_host=vodshieldgroup001 method=GET parent=“1.1.1.1:80;" round_robin=consistent_hash qstring=ignore >> >> ** remap.conf >> map http://trafficserver_ram/ http://liveshieldgroup001/ >> map http://trafficserver_disk/ http://vodshieldgroup001/ >> >> If I do a GET-request, it fails in a “502 Server not found”: >> >> T 127.0.0.1:39062 -> 127.0.0.1:8080 [AP] #24 >> GET /test HTTP/1.1. >> Host: trafficserver_ram. >> X-Real-IP: 2.2.2.2. >> X-Forwarded-For: 2.2.2.2. >> Connection: upgrade. >> Accept: */*. >> . >> >> T 127.0.0.1:8080 -> 127.0.0.1:39062 [AP] #26 >> HTTP/1.1 502 Cannot find server.. >> Date: Tue, 11 Dec 2018 17:18:18 GMT. >> Connection: keep-alive. >> Server: ATS/7.1.2. >> Cache-Control: no-store. >> Content-Type: text/html. >> Content-Language: en. >> Content-Length: 2. >> . >> >> During this request I *do* see ATS doing DNS requests: >> 1 0.000000000 x.x.x.x → 8.8.8.8 DNS 78 Standard query 0x6a81 AAAA liveshieldgroup001 >> 2 0.005837695 8.8.8.8 → x.x.x.x DNS 153 Standard query response 0x6a81 No such name AAAA liveshieldgroup001 SOA a.root-servers.net >> 3 0.005899611 x.x.x.x → 8.8.8.8 DNS 78 Standard query 0xf4f3 AAAA liveshieldgroup001 >> 4 0.011621809 8.8.8.8 → x.x.x.x DNS 153 Standard query response 0xf4f3 No such name AAAA liveshieldgroup001 SOA a.root-servers.net >> >> I have checked with "traffic_ctl config diff” and see only the entries above as non-standard. >> Software used is the stock ATS from Ubuntu 18.04: trafficserver 7.1.2+ds-3 >> >> Am I hitting a bug, or missing something obvious? >> Thanks for any replies. >> >> -- >> Met vriendelijke groet, >> >> Theo Hoogerheide >> Lead Infrastructure Architect >> >
