On Sun, Feb 28, 2010 at 8:36 AM, Barry Margolin <bar...@alum.mit.edu> wrote: > In article <mailman.666.1267335206.21153.bind-us...@lists.isc.org>, > Tory M Blue <tmb...@gmail.com> wrote: > >> I've running into some issues and trying to diagnose, so maybe folks >> on here can help me with steps to troubleshoot. >> >> Bind 9.6.1-P1 >> Fedora Core >> >> What I am experiencing and led to my investigation is a random 5 >> second delay in name resolution. Now I know that nslookup/dig resolver >> has a default 5 second retry, if it doesn't get an answer it will try >> the second server listed in the resolv.conf.. So I sort of could >> explain the 5 second delay, didn't understand why it was happening, >> but felt I was getting closer. >> >> So then I started running some network traces (which takes some time, >> as the 5 second delay is very random}, however being patient and >> running enough "time dig host +trace" revealed a few 5 second delays, >> for the most part they are all low ms (as I expect), but a couple were >> 5 second. >> >> The delay occurs in the upper part of dig. (although interesting >> enough not one section shows more than say 175ms, ever). >> >> [tb...@w05 ~]$ time dig apps.domain.com +trace +stats >> >> ; <<>> DiG 9.3.2 <<>> apps.domain.com +trace +stats >> ;; global options: printcmd >> . 317993 IN NS C.ROOT-SERVERS.NET. >> . 317993 IN NS J.ROOT-SERVERS.NET. >> . 317993 IN NS B.ROOT-SERVERS.NET. >> . 317993 IN NS L.ROOT-SERVERS.NET. >> . 317993 IN NS D.ROOT-SERVERS.NET. >> . 317993 IN NS I.ROOT-SERVERS.NET. >> . 317993 IN NS F.ROOT-SERVERS.NET. >> . 317993 IN NS G.ROOT-SERVERS.NET. >> . 317993 IN NS M.ROOT-SERVERS.NET. >> . 317993 IN NS K.ROOT-SERVERS.NET. >> . 317993 IN NS A.ROOT-SERVERS.NET. >> . 317993 IN NS H.ROOT-SERVERS.NET. >> . 317993 IN NS E.ROOT-SERVERS.NET. >> >> <<<<PAUSES HERE>>>>> > > I think it's trying to do a reverse lookup of 216.249.24.15 to display > the server name in the message below. This isn't part of the actual > resolution of apps.domain.com, just part of +stats. So it may not be > related to your original problem. > >> ;; Query time: 1 msec >> ;; SERVER: 0.0.0.15#53(216.249.24.15) >> ;; WHEN: Sat Feb 27 21:25:21 2010 >> ;; MSG SIZE rcvd: 500 >> >> net. 172800 IN NS H.GTLD-SERVERS.net. >> net. 172800 IN NS M.GTLD-SERVERS.net. >> net. 172800 IN NS I.GTLD-SERVERS.net. >> net. 172800 IN NS F.GTLD-SERVERS.net. >> net. 172800 IN NS K.GTLD-SERVERS.net. >> net. 172800 IN NS L.GTLD-SERVERS.net. >> net. 172800 IN NS E.GTLD-SERVERS.net. >> net. 172800 IN NS J.GTLD-SERVERS.net. >> net. 172800 IN NS D.GTLD-SERVERS.net. >> net. 172800 IN NS G.GTLD-SERVERS.net. >> net. 172800 IN NS B.GTLD-SERVERS.net. >> net. 172800 IN NS A.GTLD-SERVERS.net. >> net. 172800 IN NS C.GTLD-SERVERS.net. >> ;; Query time: 14 msec >> ;; SERVER: 192.33.4.12#53(C.ROOT-SERVERS.NET) >> ;; WHEN: Sat Feb 27 21:25:21 2010 >> ;; MSG SIZE rcvd: 505 >> >> domain.com. 172800 IN NS ns1.domain.com. >> domain.com. 172800 IN NS ns2.domain.com. >> ;; Query time: 54 msec >> ;; SERVER: 192.55.83.30#53(M.GTLD-SERVERS.net) >> ;; WHEN: Sat Feb 27 21:25:26 2010 >> ;; MSG SIZE rcvd: 104 >> >> apps.domain.com. 300 IN A 216.249.24.50 >> domain.com. 86400 IN NS ns2.domain.com. >> domain.com. 86400 IN NS ns1.domain.com. >> ;; Query time: 0 msec >> ;; SERVER: 0.0.0.15#53(ns1.domain.com) >> ;; WHEN: Sat Feb 27 21:25:26 2010 >> ;; MSG SIZE rcvd: 120 >> >> >> real 0m5.090s >> user 0m0.004s >> sys 0m0.004s >> >> So since I finally caught one of these in the wild, I could look at >> the network trace. I was caught off guard when I saw "No such Name" >> "Flags: 0x8483 (Standard query response, No such name)" > > It would help if you told us WHICH query elicited this response.
Thanks for the info. the query was a standard A record, it came with the same command ; time dig apps.domain.com +trace. the 5 second delay is just really odd and trying to run it down. Is there more debug type logs I could turn on that would yield more information? Thanks Tory _______________________________________________ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
