[Pdns-users] gmysql-host weirdness

[Mark Moseley]

I don't know if this is a bug or not, but it certainly confused me.

I usually have an IP in the gmysql-host config item in pdns.conf. I
was being clever and switched it to a hostname in an internal domain.
That internal domain is served via Bind 9 on another set of boxes but
as it happens, the internal domain happened to exist in the mysql
tables that pdns was connecting to (we use Pdns for our external
nameservers -- i.e. for the rest of the world to resolve against).

The odd behaviour was that when pdns started up, what I'm assuming was
the parent or parent thread (we have 8 distributor-threads running)
connected to the correct IP, so it must've used the system resolver to
resolve the hostname. However the subsequent threads used the data
from the pdns tables to resolve the hostname, which since the internal
domain wasn't really supposed to be there in the first place, yielded
the wrong data thanks to a wildcard record. /etc/resolv.conf does not
have 127.0.0.1 as a nameserver. So basically one thread (or parent)
used the system resolver to resolve the hostname of the database
server, then the subsequent ones used themselves to resolve it. I can
see why it would do that, but it seems a bit inconsistent to use
different name resolution processes.

Not exactly earth shattering obviously, but I figured I'd mention it,
since it was pretty bewildering at first. It might be mentioned in the
docs somewhere too but I didn't see it in the Configuring MySQL
section.

BTW, I love PowerDNS! Keep up the great work!