This is queryperf, a DNS server query performance testing tool.

It is primarily intended for measuring the performance of
authoritative DNS servers, but it has also been used for measuring
caching server performance.  This document describes the use of
queryperf for authoritative server performance testing.


Building

To build queryperf, just do

  sh configure
  make


The test environment

It is recommended that you run queryperf and the name server under
test on separate machines, so that the CPU usage of queryperf itself
does not slow down the name server.  The two machines should be
connected with a fast network, preferably a dedicated 100baseT
segment.  Testing through a router or firewall is not advisable.


Configuring the server

The name server under test should be set up as an authoritative
server, serving one or more zones similar in size and number to
what the server is expected to serve in production.

Be sure to turn off recursion in the server's configuration 
(in BIND 8/9, specify "recursion no;" in the options block).
In BIND 8, you should also specify "fetch-glue no;"; otherwise
the server may attempt to retrieve glue information from the
Internet during the test, slowing it down by an unpredictable
factor.


Constructing the input file

You need to construct a queryperf input file containing a large and
realistic set of queries, on the order of ten thousand to a million.
The input file contains one line per query, consisting of a domain 
name and an RR type name separated by a space.  The class of the 
query is implicitly IN.

When measuring the performance serving non-terminal zones such as the
root zone or TLDs, note that such servers spend most of their time
providing referral responses, not authoritative answers.  Therefore, a
realistic input file might consist mostly of queries for type A for
names *below*, not at, the delegations present in the zone.  For
example, when testing the performance of a server configured to be
authoritative for the top-level domain "fi.", which contains
delegations for domains like "helsinki.fi" and "turku.fi", the input
file could contain lines like

  www.turku.fi A
  www.helsinki.fi A

where the "www" prefix ensures that the server will respond with a
referral.  Ideally, a realistic proportion of queries for nonexistent
domains should be mixed in with those for existing ones, and the lines
of the input file should be in a random order.


Running the tests

Queryperf is run specifying the input file using the "-d" option, as
in

  queryperf -d input_file -s server

The output of queryperf is mostly self-explanatory.  Pay attention to
the number of dropped packets reported - when running the test over a
local Ethernet connection, it should be zero.  If one or more packets
has been dropped, there may be a problem with the network connection.
In that case, the results should be considered suspect and the test
repeated.
