[Pdns-users] pdns stops responding to UDP queries, gets signal 11 a lot.

Fri Apr 28 18:19:40 UTC 2006

I have a couple servers running pdns 2.9.18 (from ubuntu breezy), with
a mysql backend, using mysql replication to keep them in sync. After a
few days they'll stop responding to udp name queries, but tcp queries
will keep working. If I reload the pdns server, udp queries will then
start working again. They don't stop at the same time, it seems
random. I don't yet have automated monitoring for these servers, so
I'm not sure yet exactly when they stop working (if it's always at the
same time of day, etc).

Looking through the logs, pdns seems to be getting signal 11 an awful
lot, as much as every few hours. Both machines are getting them, and
run fine otherwise, so I don't think it's bad ram or anything. Below
are examples of log entries, one from each box. Please let me know if
there's any other info that would be helpful, I'm happy to provide it.

Apr 27 03:09:18 ns1 pdns[24653]: Got a signal 11, attempting to print trace:
Apr 27 03:09:18 ns1 pdns[24653]: /usr/sbin/pdns_server-instance [0x80c6184]
Apr 27 03:09:18 ns1 pdns[24653]: [0xffffe420]
Apr 27 03:09:18 ns1 pdns[24653]: Got a signal 11, attempting to print trace:
Apr 27 03:09:18 ns1 pdns[24653]: /usr/lib/libstdc++.so.6(_ZN9__gnu_cxx6__poolILb1EE16_M_reclaim_blockEPcj+0x91) [0xb7f263b1]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/lib/libstdc++.so.6 [0xb7f26a82]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/sbin/pdns_server-instance [0x80c6184]
Apr 27 03:09:18 ns1 pdns[24653]: [0xffffe420]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/lib/libstdc++.so.6(_ZN9__gnu_cxx6__poolILb1EE16_M_reclaim_blockEPcj+0x91) [0xb7f263b1]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/lib/libstdc++.so.6 [0xb7f26a82]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/lib/libstdc++.so.6(_ZNSs4_Rep10_M_destroyERKSaIcE+0x38) [0xb7f74e68]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/lib/libstdc++.so.6(_ZNSs7reserveEj+0x165) [0xb7f76ed5]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/lib/libstdc++.so.6(_ZNSs6appendEPKcj+0x55) [0xb7f77145]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/sbin/pdns_server-instance(_ZN9DNSPacket8compressERKSs+0xd3) [0x8067c39]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/sbin/pdns_server-instance(_ZN9DNSPacket7toqnameEPKcRSsb+0x49) [0x806a30b]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/sbin/pdns_server-instance(_ZN9DNSPacket12addSOARecordERKSsS1_jN17DNSResourceRecord5PlaceE+0xb5) [0x806c8fd]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/sbin/pdns_server-instance(_ZN9DNSPacket12addSOARecordERK17DNSResourceRecord+0x30) [0x806cc4c]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/sbin/pdns_server-instance(_ZN9DNSPacket6wrapupEv+0xbfa) [0x806e78e]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/sbin/pdns_server-instance(_ZN13PacketHandler8questionEP9DNSPacket+0x1099) [0x809112d]
Apr 27 03:09:18 ns1 pdns[24653]: /usr/sbin/pdns_server-instance(_ZN11DistributorI9DNSPacketS0_13PacketHandlerE10makeThreadEPv+0x165) [0x81005e5]
Apr 27 03:09:18 ns1 pdns[24653]: /lib/tls/libpthread.so.0 [0xb7eab20e]
Apr 27 03:09:18 ns1 pdns[24653]: /lib/tls/libc.so.6(__clone+0x5e) [0xb7e4105e]
Apr 27 03:09:18 ns1 pdns[23401]: Our pdns instance (24653) exited after signal 6
Apr 27 03:09:18 ns1 pdns[23401]: Respawning
Apr 27 03:09:19 ns1 pdns[24898]: Guardian is launching an instance
Apr 27 03:09:19 ns1 pdns[24898]: This is module gmysqlbackend.so reporting
Apr 27 03:09:19 ns1 pdns[24898]: This is a guarded instance of pdns
Apr 27 03:09:19 ns1 pdns[24898]: It is advised to bind to explicit addresses with the --local-address option
Apr 27 03:09:19 ns1 pdns[24898]: UDP server bound to 0.0.0.0:53 Apr 27 03:09:19 ns1 pdns[24898]: TCP server bound to 0.0.0.0:53
Apr 27 03:09:19 ns1 pdns[24898]: PowerDNS 2.9.18 (C) 2001-2005 PowerDNS.COM BV (Aug  1 2005, 15:20:34, gcc 4.0.2 20050729 (prerelease) (Debian 4.0.1-4ubuntu1)) starting up Apr 27 03:09:19 ns1 pdns[24898]: PowerDNS comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to redistribute it according to the terms of the GPL version 2.
Apr 27 03:09:19 ns1 pdns[24898]: Set effective group id to 111
Apr 27 03:09:19 ns1 pdns[24898]: Set effective user id to 105
Apr 27 03:09:19 ns1 pdns[24898]: Creating backend connection for TCP
Apr 27 03:09:19 ns1 pdns[24898]: gmysql Connection succesful
Apr 27 03:09:19 ns1 pdns[24898]: About to create 3 backend threads for UDP
Apr 27 03:09:19 ns1 pdns[24898]: gmysql Connection succesful
Apr 27 03:09:26 ns1 last message repeated 3 times

Apr 27 12:34:59 ns2 pdns[16252]: Got a signal 11, attempting to print trace:
Apr 27 12:34:59 ns2 pdns[16252]: /usr/sbin/pdns_server-instance [0x80c6184]
Apr 27 12:34:59 ns2 pdns[16252]: [0xffffe420] Apr 27 12:34:59 ns2 pdns[16252]: /usr/lib/libstdc++.so.6(_ZN9__gnu_cxx6__poolILb1EE16_M_reclaim_blockEPcj+0x91) [0xb7f253b1]
Apr 27 12:34:59 ns2 pdns[16252]: /usr/lib/libstdc++.so.6 [0xb7f25a82] Apr 27 12:34:59 ns2 pdns[16252]: /usr/lib/libstdc++.so.6(_ZNSs4_Rep10_M_destroyERKSaIcE+0x38) [0xb7f73e68] Apr 27 12:34:59 ns2 pdns[16252]: /usr/lib/libstdc++.so.6(_ZNSsD1Ev+0x101) [0xb7f75d51]
Apr 27 12:34:59 ns2 pdns[16252]: /usr/sbin/pdns_server-instance(_ZN12UeberBackend8cacheHasERKNS_8QuestionER17DNSResourceRecord+0x155) [0x80cf097]
Apr 27 12:34:59 ns2 pdns[16252]: /usr/sbin/pdns_server-instance(_ZN12UeberBackend6lookupERK5QTypeRKSsP9DNSPacketi+0x315) [0x80cfb2b] Apr 27 12:34:59 ns2 pdns[16252]: /usr/sbin/pdns_server-instance(_ZN13PacketHandler11makeCanonicEP9DNSPacketS1_RSs+0xab) [0x808f92d]
Apr 27 12:34:59 ns2 pdns[16252]: /usr/sbin/pdns_server-instance(_ZN13PacketHandler8questionEP9DNSPacket+0xd96) [0x8090e2a]
Apr 27 12:34:59 ns2 pdns[16252]: /usr/sbin/pdns_server-instance(_ZN11DistributorI9DNSPacketS0_13PacketHandlerE10makeThreadEPv+0x165) [0x81005e5] Apr 27 12:34:59 ns2 pdns[16252]: /lib/tls/libpthread.so.0 [0xb7eac1ee]
Apr 27 12:34:59 ns2 pdns[16252]: /lib/tls/libc.so.6(__clone+0x5e) [0xb7e4203e] Apr 27 12:35:00 ns2 pdns[9715]: Our pdns instance (16252) exited after signal 6
Apr 27 12:35:00 ns2 pdns[9715]: Respawning
Apr 27 12:35:01 ns2 pdns[16729]: Guardian is launching an instance
Apr 27 12:35:01 ns2 pdns[16729]: This is module gmysqlbackend.so reporting
Apr 27 12:35:01 ns2 pdns[16729]: This is a guarded instance of pdns
Apr 27 12:35:01 ns2 pdns[16729]: It is advised to bind to explicit addresses with the --local-address option
Apr 27 12:35:01 ns2 pdns[16729]: UDP server bound to 0.0.0.0:53
Apr 27 12:35:01 ns2 pdns[16729]: TCP server bound to 0.0.0.0:53
Apr 27 12:35:01 ns2 pdns[16729]: PowerDNS 2.9.18 (C) 2001-2005 PowerDNS.COM BV (Aug  1 2005, 15:20:34, gcc 4.0.2 20050729 (prerelease) (Debian 4.0.1-4ubuntu1)) starting up
Apr 27 12:35:01 ns2 pdns[16729]: PowerDNS comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to redistribute it according to the terms of the GPL version 2.
Apr 27 12:35:01 ns2 pdns[16729]: Set effective group id to 109
Apr 27 12:35:01 ns2 pdns[16729]: Set effective user id to 108
Apr 27 12:35:01 ns2 pdns[16729]: Creating backend connection for TCP
Apr 27 12:35:01 ns2 pdns[16729]: gmysql Connection succesful
Apr 27 12:35:01 ns2 pdns[16729]: About to create 3 backend threads for UDP
Apr 27 12:35:01 ns2 pdns[16729]: gmysql Connection succesful
Apr 27 12:35:07 ns2 last message repeated 3 times