2015-01-27 13:21 GMT-03:00 Ciro Iriarte <cyru...@gmail.com>: > 2015-01-27 6:59 GMT-03:00 bert hubert <bert.hub...@powerdns.com>: > > On Sun, Jan 25, 2015 at 10:33:34AM -0300, Ciro Iriarte wrote: >> > Also, the test traffic was stopped, so the trace file should be complete >> > and cleaner!. >> >> Ciro, >> >> I don't see anything that is wrong here. From a cold cache, it takes 11 >> queries to resolve 2.centos.pool.ntp.org. >> >> Your network used up the following amounts of time on those queries: >> in 266ms >> in 226ms >> in 184ms >> in 226ms >> in 233ms >> in 267ms >> in 223ms >> in 201ms >> in 224ms >> in 51ms >> in 199ms >> >> Which together is around 2 seconds. >> >> If there is a problem, the problem is that your network is pretty far away >> from most servers it appears. >> >> If you redo your query with the latest PowerDNS test version (3.7.0-RC1) >> you'll get slightly better timing output with --trace, which perhaps could >> tell you a little more. >> >> On a high-latency network (and your fastest response to anything in this >> trace was 51ms, even if I look at the other queries too), having a warm >> cache is super important. >> >> Good luck! >> >> Bert >> > > Hi Bert, thanks for the analysis!. I double checked all the configuration > (routing/pdns/linux) and everything seems to be OK. It's obviously not a > PDNS thing as a trace using dig still gives pretty bad times > > ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.30.rc1.el6 <<>> +trace > 2.centos.pool.ntp.org > ;; Received 241 bytes from 186.16.16.16#53(186.16.16.16) in 1317 ms <--- > this goes to localhost for recursion > ;; Received 441 bytes from 199.7.83.42#53(199.7.83.42) in 5628 ms > ;; Received 153 bytes from 199.19.57.1#53(199.19.57.1) in 2881 ms > ;; Received 189 bytes from 128.175.13.17#53(128.175.13.17) in 8346 ms > ;; Received 187 bytes from 94.242.223.210#53(94.242.223.210) in 644 ms > > Complete trace: > http://pastebin.com/tvKqhq2e > > What I find weird is that a query to the server 199.7.83.42 takes more > than 5 seconds, but a plain ping request gives a RTT of about 177ms. Maybe > the servers are overloaded and I'm over-reacting :P > > --- 199.7.83.42 ping statistics --- > 5 packets transmitted, 5 received, 0% packet loss, time 4187ms > *rtt min/avg/max/mdev = 177.556/178.459/181.044/1.334 ms* > > > The same goes for the other destinations: > > --- 199.19.57.1 ping statistics --- > 5 packets transmitted, 5 received, 0% packet loss, time 4183ms > *rtt min/avg/max/mdev = 177.125/177.302/177.644/0.565 ms* > > --- 128.175.13.17 ping statistics --- > 5 packets transmitted, 5 received, 0% packet loss, time 4194ms > *rtt min/avg/max/mdev = 187.530/188.211/189.673/0.931 ms* > > > --- 94.242.223.210 ping statistics --- > 5 packets transmitted, 5 received, 0% packet loss, time 4276ms > *rtt min/avg/max/mdev = 265.467/269.252/272.820/2.637 ms* > > The only other thing I could think of is some kind of QoS issue and to > blame the carrier. It's time to poke the networking guys... > > Regards, > > -- > Ciro Iriarte > http://iriarte.it > -- >
For the record, a second query for the same fqdn responds a lot faster which implies there's some cache involved now. ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.30.rc1.el6 <<>> +trace 2.centos.pool.ntp.org ;; Received 241 bytes from 186.16.16.16#53(186.16.16.16) in 7 ms ;; Received 441 bytes from 192.33.4.12#53(192.33.4.12) in 204 ms ;; Received 153 bytes from 199.19.53.1#53(199.19.53.1) in 183 ms ;; Received 189 bytes from 128.175.13.17#53(128.175.13.17) in 187 ms ;; Received 187 bytes from 46.234.32.107#53(46.234.32.107) in 478 ms Regards, -- Ciro Iriarte http://iriarte.it --
_______________________________________________ Pdns-users mailing list Pdns-users@mailman.powerdns.com http://mailman.powerdns.com/mailman/listinfo/pdns-users
