[Dnsmasq-discuss] Reponse time is huge for big payload SRV record on dnsmasq servers
Simon Kelley
simon at thekelleys.org.uk
Wed May 9 09:04:42 BST 2018
On 09/05/18 07:48, Harish Shetty wrote:
> HI
>
> I am upgrading the dnsmasq now, But I have couple of more question, I
> read somewhere, dnsmasq can cache only A, AAAA records only.. is that
> true??
A, AAAA (some) PTR and CNAME
and multiple line caching is not supported. Is there anyway we
Not sure what you mean by "multiple line"
Simon.
> can cache the TCP query??
>
> Regards
> Harish Shetty
>
> On Wed, May 9, 2018 at 1:42 AM, Simon Kelley <simon at thekelleys.org.uk
> <mailto:simon at thekelleys.org.uk>> wrote:
>
> Check all the servers you have configured. If one is not accepting TCP
> connections, that could delay things whilst the connection attempt times
> out.
>
> If the upstream servers accept TCP connections and reply on them in a
> timely manner, I don't know what else could be causing the problem. It
> would be worth setting --log-queries to try and see where the delays
> are.
>
> 2.48 is very, very old. Can you upgrade?
>
>
> Cheers,
>
> Simon.
>
> On 07/05/18 15:30, Harish Shetty wrote:
> > Hi Simon
> >
> > Thanks for the reply, Yes you are rite, Truncated bit is set in the
> > message. I am seeing ";; Truncated, retrying in TCP mode." in the
> > answer. But it is expected and answer is more than 512 bytes (which is
> > size of UDB packet). TCP port 53 is allowed , but DNS respone time
> from
> > dnsmasq service is more than 3 sec sometime 4 or 5 sec. When we query
> > directly upstream server we are seeing the response on avg of 100 to
> > 200 ms.
> >
> > Is there anyway we can make DNS query faster in dnsmasq server,
> because
> > it is making our application timeouts.
> >
> > Regards
> > Harish Shetty
> >
> > On Mon, May 7, 2018 at 7:03 PM, Simon Kelley
> <simon at thekelleys.org.uk <mailto:simon at thekelleys.org.uk>
> > <mailto:simon at thekelleys.org.uk <mailto:simon at thekelleys.org.uk>>>
> wrote:
> >
> > That's large enough to need TCP.
> >
> > What I'd expect top happen is that the upstream server returns
> an answer
> > with the truncated bit setin the header. This answer gets
> returned by
> > dnsmasq to the original requestor. The original requestor
> makes a TCP
> > connection to dnsmasq and re-sends the query. Dnsmasq makes a TCP
> > connection upstream and send the query, and gets the result.
> It then
> > send the result back down the TCP connection to the original
> requestor.
> >
> > Anything blocking or distrupting TCP connections on port 53 is
> suspect.
> > An non-responsive upstream server will cause delays whilst the
> > connection times out.
> >
> > Try running the query direct to the upstream servers using dig +vc
> >
> > Cheers,
> >
> > Simon.
> >
> >
> > On 07/05/18 13:57, Harish Shetty wrote:
> > > Hi All
> > >
> > > I am facing some issue with dnsmasq. Currently I am using
> > dnsmasq-2.48
> > > , I am using this as my forwarder and caching sever. But my
> > problem is,
> > > when i query for a high payload SRV record (answer size is
> about 3500
> > > bytes) response time some times crosses 4000ms, and
> intermittently
> > timeout.
> > >
> > > I have tried enabling the logquries, but it didnt give much
> > information
> > > to me, Any suggestion on the debugging or more details will be
> > helpful
> > >
> > > Regards
> > > Harish Shetty
> > >
> > >
> > >
> > >
> > > _______________________________________________
> > > Dnsmasq-discuss mailing list
> > > Dnsmasq-discuss at lists.thekelleys.org.uk
> <mailto:Dnsmasq-discuss at lists.thekelleys.org.uk>
> > <mailto:Dnsmasq-discuss at lists.thekelleys.org.uk
> <mailto:Dnsmasq-discuss at lists.thekelleys.org.uk>>
> > >
> http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
> <http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss>
> >
> <http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
> <http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss>>
> > >
> >
> > _______________________________________________
> > Dnsmasq-discuss mailing list
> > Dnsmasq-discuss at lists.thekelleys.org.uk
> <mailto:Dnsmasq-discuss at lists.thekelleys.org.uk>
> > <mailto:Dnsmasq-discuss at lists.thekelleys.org.uk
> <mailto:Dnsmasq-discuss at lists.thekelleys.org.uk>>
> >
> http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
> <http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss>
> >
> <http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
> <http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss>>
> >
> >
>
>
More information about the Dnsmasq-discuss
mailing list