[Pdns-users] Possible tcp listener issue

[Laurent Papier]

Le Thu, 25 Mar 2010 19:34:11 +0100
bert hubert <bert.hubert at netherlabs.nl> écrit:

> On Thu, Mar 25, 2010 at 05:54:23PM +0100, Laurent Papier wrote:
> 
> > I have also upgraded to pdns recursor 3.2 yesterday. And today, I have a strange
> > problem on some of my systems. It seems be related to tcp DNS as the only thing
> > that stopped working is using tcp dns queries. The rest of the system worked
> > fine. 
> 
> Ok, that makes two reports of the same thing.
> 
> When this happens, do you experience timeouts on TCP queries? Or connection
> refused? Or just servfail answers?

When this happened, I have quickly checked if dns recursor still answer dns
queries with dig. And it still replied even to the big MX entry I suspect.
Maybe I was too fast or did not read the dig output well enough. I need to
double check this next time it happens.

But Simon report makes me think that something could be wrong with tcp in
version 3.2. I'm sorry that I don't have more precise report for the moment.

> Can you check if this happens again before restarting?

Sure I will.

> 
> In addition, OS details would be appreciated (as Leen has pointed out too).

Some technical info :
- home made and compiled RPM for Redhat system (gcc 3.3, boost 1.34.1, kernel
2.6.24.5).
- threads=2 setting, listen to 127.0.0.1 only.

I have switched to threads=1, in the hope that the problem maybe related to
thread (version 3.1.7.2 works very well on the same system).

I'm also thinking of a solution to change the MX entry fit in a UDP dns packet
as it seems that the packet cache is only used for UDP.

-- 
Laurent Papier - 03 88 75 80 50
Admin. système - SdV Plurimedia - <http://www.sdv.fr/>