[Samba] samba dns issues

[David Bear]

We are using samba 4.1.9 complied from source.

We have been running as an AD DC for 5 months.

Lately, we have noticed that samba processor seem to consume the entire
system, using all cpu cycles. This happens within about 30 minutes of
starting or restating the samba daemons. When Samba slows down, the first
issue that comes up is that dns name resolutions time out for any client
asking for names in the AD DC zone.

We did a basic samba provision, so content of the smb.conf file is pretty
generic. We are using the internal samba dns. We have the dns forward
option set in samba to point to our firewall. We are running dnsmasq on the
firewall as our caching name server.

We set debug level to 3 and started captureing log.samba entries. I'm
guessing the entries that I should be concerned about are the
connection_refused and the connection_disconnect - but then I'm guessing.

Can anyone tell me if these entries are 'normal' and if not, what they mean?

-------------------------------------
[2014/12/16 15:56:41.101869,  1] ../librpc/ndr/ndr.c:296(ndr_print_debug)
       discard_const(update): struct dns_res_rec
          name                     : 'HAServer1.ad.ha.net'
          rr_type                  : DNS_QTYPE_AAAA (0x1C)
          rr_class                 : DNS_QCLASS_ANY (0xFF)
          ttl                      : 0x00000000 (0)
          length                   : 0x0000 (0)
          rdata                    : union dns_rdata(case 0x1C)
          ipv6_record              : (null)
          unexpected               : DATA_BLOB length=0
[2014/12/16 15:56:41.105890,  2]
../source4/dns_server/dns_update.c:398(handle_one_update)
  Looking at record:
[2014/12/16 15:56:41.106125,  2]
../source4/dns_server/dns_update.c:399(handle_one_update)
[2014/12/16 15:56:41.106169,  1] ../librpc/ndr/ndr.c:296(ndr_print_debug)
       discard_const(update): struct dns_res_rec
          name                     : 'HAServer1.ad.ha.net'
          rr_type                  : DNS_QTYPE_A (0x1)
          rr_class                 : DNS_QCLASS_ANY (0xFF)
          ttl                      : 0x00000000 (0)
          length                   : 0x0000 (0)
          rdata                    : union dns_rdata(case 0x1)
          ipv4_record              : (null)
          unexpected               : DATA_BLOB length=0
[2014/12/16 15:56:41.108341,  0]
../source4/librpc/rpc/dcerpc_sock.c:262(continue_socket_connect)
  Failed to connect host 10.2.10.10 on port 135 -
NT_STATUS_CONNECTION_REFUSED
[2014/12/16 15:56:41.109200,  0]
../source4/librpc/rpc/dcerpc_sock.c:425(continue_ip_open_socket)
  Failed to connect host 10.2.10.10 (75566c2f-274e-485c-809a-b63fd5a29b11._
msdcs.ad.ha.net) on port 135 - NT_STATUS_CONNECTION_REFUSED.
[2014/12/16 15:56:41.823458,  3]
../source4/smbd/service_stream.c:66(stream_terminate_connection)
  Terminating connection - 'dcesrv: NT_STATUS_CONNECTION_DISCONNECTED'
[2014/12/16 15:56:41.824117,  3]
../source4/smbd/process_single.c:114(single_terminate)
  single_terminate: reason[dcesrv: NT_STATUS_CONNECTION_DISCONNECTED]
[2014/12/16 15:56:41.824662,  3]
../source4/smbd/service_stream.c:66(stream_terminate_connection)
  Terminating connection - 'dcesrv: NT_STATUS_CONNECTION_DISCONNECTED'
[2014/12/16 15:56:41.825251,  3]
../source4/smbd/process_single.c:114(single_terminate)
  single_terminate: reason[dcesrv: NT_STATUS_CONNECTION_DISCONNECTED]
[2014/12/16 15:56:45.277232,  3]
../source4/smbd/service_stream.c:66(stream_terminate_connection)
  Terminating connection - 'dcesrv: NT_STATUS_CONNECTION_DISCONNECTED'
[2014/12/16 15:56:45.277679,  3]
../source4/smbd/process_single.c:114(single_terminate)
  single_terminate: reason[dcesrv: NT_STATUS_CONNECTION_DISCONNECTED]
[2014/12/16 15:56:46.322355,  2]
../source4/dns_server/dns_update.c:398(handle_one_update)
  Looking at record:
[2014/12/16 15:56:46.322578,  2]
../source4/dns_server/dns_update.c:399(handle_one_update)
[2014/12/16 15:56:46.322621,  1] ../librpc/ndr/ndr.c:296(ndr_print_debug)
       discard_const(update): struct dns_res_rec
          name                     : 'HAServer1.ad.ha.net'
          rr_type                  : DNS_QTYPE_A (0x1)
          rr_class                 : DNS_QCLASS_IN (0x1)
          ttl                      : 0x000004b0 (1200)
          length                   : 0x0004 (4)
          rdata                    : union dns_rdata(case 0x1)
          ipv4_record              : 10.1.10.11
          unexpected               : DATA_BLOB length=0





-- 
David Bear
mobile: (602) 903-6476