[Pdns-users] problems resolving CNAME's with pdns_recursor 3.1.7

[bert hubert]

On Thu, Jul 16, 2009 at 2:13 PM, Tom Mueller<t.mueller at strato-rz.de> wrote:
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> Hi,
>
> sometimes the pdns_recursor doesn't send all A or AAAA records where
> the requested CNAME points to.

Tom,

Do you run with an IPv6 local query address enabled? Can you,
privately, send me the full host names involved?

And a copy of your configuration file too?

Do you see this problem only on rz-ip.net?

Thanks.


> There are no cascading CNAMES, the CNAME points to an A record.
> In the first query the A records are missing, some seconds (and
> several more requests) later the A records were sent, too
> The TTL shows that the records are fetched by pdns_recursor in the
> same second.
> Hint: the 'X' in hostnames and IP addresses is a replacement of other
> chars and digits.
>
> Additional informations:
> We are running 2 instances of pdns_recursor listening at different
> ports on this IP to scale the amount of queries.
> The  concerning instance has a load average of round about 1500 qps.
>
>
> There are no error messages in the log - so I wonder what's happened?
> There is another issue that sometimes existing AAAA records of another
> host not sent but only the A records.
>
> I think, when there was an error condition during recursion the
> pdns_recursor has to sent a SERVFAIL, but it didn't.
> So it may be possible that there is an issue in the cache management
> when a refresh is needed it is not performed immediately?
> Any idea?