Performance Improvement

Peter Dambier peter at
Wed Nov 9 08:02:34 UTC 2005

christ lee wrote:
> Hi all,
> I am studying query.c, client.c in BIND9 source code. can u suggest me where
> to optimize
> the code in order to improve the performance i.e by decreasing the time
> taken by the name server.
> Expecting ur Suggestions........

Look where the time is spent.

Searching in memory - forget it.

Sending a query to another nameserver and waiting for the answer - 80 msec.
This is a typical echo/response time for DTAG.DE one of germanies biggest isps.

So querying '.' takes 80 msec.
Querying '.com' is another 80 msec.
Querying them who are responsible, yet another 80 msec.

All together 240 msec.

A typical answer for somebody not in the cache of my isp takes 2 seconds.
If the answer is in the cache I get it after only 80 msec.

You can get rid of the 80 msec for '.' by getting a copy of the root zone.
You can dramatically save time by running a copy of the zone you want to

By rewriting client.c and query.c you wont get more than a single msec.

You are studying client.c and query.c. Is that an antropology class?

Peter and Karin

Peter and Karin Dambier
The Public-Root Consortium
Graeffstrasse 14
D-64646 Heppenheim
+49(6252)671-788 (Telekom)
+49(179)108-3978 (O2 Genion)
+49(6252)750-308 (VoIP:
mail: peter at
mail: peter at

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