[Pdns-users] unix socket explosions

[David Hawthorne]

Scenario:

I'm testing a new backend that I've written and the actual backend isn't running properly so all queries are timing out.  This is ok.

I am noticing that under steady but slow request load, powerdns is spawning 2 new unix sockets every 5 seconds or so.  I am now up to 1003 open sockets for the pdns_server process.  Why might this be?

Here is a verbose log from what I see on stdout while running the server for this test:

Jul 30 22:59:43 Received a packet 31 bytes long from 127.0.0.1
Jul 30 22:59:43 DNSPacket copy constructor called!
Jul 30 22:59:43 Distributor has 0 threads available
Jul 30 22:59:43 Distributor misses a thread (0<4), spawning new one
created new ahuexception with reason: socket timeout
Jul 30 22:59:44 Caught an exception instantiating a backend, cleaning up
Jul 30 22:59:44 Received a packet 31 bytes long from 127.0.0.1
Jul 30 22:59:44 DNSPacket copy constructor called!
Jul 30 22:59:44 Distributor has 0 threads available
Jul 30 22:59:45 Received a packet 31 bytes long from 127.0.0.1
Jul 30 22:59:45 DNSPacket copy constructor called!
Jul 30 22:59:45 Distributor has 0 threads available
Jul 30 22:59:46 Received a packet 31 bytes long from 127.0.0.1
Jul 30 22:59:46 DNSPacket copy constructor called!
Jul 30 22:59:46 Distributor has 0 threads available
Jul 30 22:59:47 Received a packet 31 bytes long from 127.0.0.1
Jul 30 22:59:47 DNSPacket copy constructor called!
Jul 30 22:59:47 Distributor has 0 threads available
Jul 30 22:59:48 Received a packet 31 bytes long from 127.0.0.1
Jul 30 22:59:48 DNSPacket copy constructor called!
Jul 30 22:59:48 Distributor has 0 threads available
Jul 30 22:59:49 Received a packet 31 bytes long from 127.0.0.1
Jul 30 22:59:49 DNSPacket copy constructor called!
Jul 30 22:59:49 Distributor has 0 threads available
Jul 30 22:59:49 Distributor misses a thread (0<4), spawning new one
created new ahuexception with reason: socket timeout
Jul 30 22:59:50 Caught an exception instantiating a backend, cleaning up
Jul 30 22:59:50 Received a packet 31 bytes long from 127.0.0.1
Jul 30 22:59:50 DNSPacket copy constructor called!
Jul 30 22:59:50 Distributor has 0 threads available

it continues like this indefinitely