DNSPERF(1) Nominum DNSPERF(1)NAMEdnsperf - test the performance of a DNS server
SYNOPSISdnsperf [-a local_addr] [-b bufsize] [-c clients] [-d datafile] [-D]
[-e] [-f family] [-h] [-l limit] [-n runs_through_file] [-p port]
[-q num_queries] [-Q max_qps] [-s server_addr] [-S stats_interval]
[-t timeout] [-u] [-v] [-x local_port] [-y [alg:]name:secret]
DESCRIPTIONdnsperf is a DNS server performance testing tool. It is primarily in‐
tended for measuring the performance of authoritative DNS servers, but
it can also be used for measuring caching server performance in a
closed laboratory environment. For testing caching servers resolving
against the live Internet, the resperf program is preferred.
It is recommended that dnsperf and the name server under test be run on
separate machines, so that the CPU usage of dnsperf itself does not
slow down the name server. The two machines should be connected with a
fast network, preferably a dedicated Gigabit Ethernet segment. Testing
through a router or firewall is not advisable.
Configuring the name server
If using dnsperf to test an authoritative server, the name server under
test should be set up to serve one or more zones similar in size and
number to what the server is expected to serve in production.
Also, 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 a query input file
A dnsperf input file should contain a large and realistic set of
queries, on the order of ten thousand to a million. The input file con‐
tains 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 pro‐
viding referral responses, not authoritative answers. Therefore, a re‐
alistic 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 re‐
ferral. Ideally, a realistic proportion of queries for nonexistent do‐
mains should be mixed in with those for existing ones, and the lines of
the input file should be in a random order.
Constructing a dynamic update input file
To test dynamic update performance, dnsperf is run with the -u option,
and the input file is constructed of blocks of lines describing dynamic
update messages. The first line in a block contains the zone name:
example.com
Subsequent lines contain prerequisites, if there are any. Prerequisites
can specify that a name may or may not exist, an rrset may or may not
exist, or an rrset exists and its rdata matches all specified rdata for
that name and type. The keywords "require" and "prohibit" are followed
by the appropriate information. All relative names are considered to be
relative to the zone name. The following lines show the 5 types of pre‐
requisites.
require a
require a A
require a A 1.2.3.4
prohibit x
prohibit x A
Subsequent lines contain records to be added, records to be deleted,
rrsets to be deleted, or names to be deleted. The keywords "add" or
"delete" are followed by the appropriate information. All relative
names are considered to be relative to the zone name. The following
lines show the 4 types of updates.
add x 3600 A 10.1.2.3
delete y A 10.1.2.3
delete z A
delete w
Each update message is terminated by a line containing the command:
send
Running the tests
When running dnsperf, a data file (the -d option) and server (the -s
option) will normally be specified. The output of dnsperf is mostly
self-explanatory. Pay attention to the number of dropped packets re‐
ported - 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.
OPTIONS-a local_addr
Specifies the local address from which to send requests. The de‐
fault is the wildcard address.
-b bufsize
Sets the size of the socket's send and receive buffers, in kilo‐
bytes. If not specified, the operating system's default is used.
-c clients
Act as multiple clients. Requests are sent from multiple sock‐
ets. The default is to act as 1 client.
-d datafile
Specifies the input data file. If not specified, dnsperf will
read from standard input.
-D
Sets the DO (DNSSEC OK) bit [RFC3225] in all packets sent. This
also enables EDNS0, which is required for DNSSEC.
-e
Enables EDNS0 [RFC2671], by adding an OPT record to all packets
sent.
-f family
Specifies the address family used for sending DNS packets. The
possible values are "inet", "inet6", or "any". If "any" (the de‐
fault value) is specified, dnsperf will use whichever address
family is appropriate for the server it is sending packets to.
-h
Print a usage statement and exit.
-l limit
Specifies a time limit for the run, in seconds. This may cause
the input to be read multiple times, or only some of the input
to be read. The default behavior is to read the input once, and
have no specific time limit.
-n runs_through_file
Run through the input file at most this many times. If no time
limit is set, the file will be read exactly this number of
times; if a time limit is set, the file may be read fewer times.
-p port
Sets the port on which the DNS packets are sent. If not speci‐
fied, the standard DNS port (53) is used.
-q num_queries
Sets the maximum number of outstanding requests. When this value
is reached, dnsperf will not send any more requests until either
responses are received or requests time out. The default value
is 100.
-Q max_qps
Limits the number of requests per second. There is no default
limit.
-s server_addr
Specifies the name or address of the server to which requests
will be sent. The default is the loopback address, 127.0.0.1.
-S stats_interval
If this parameter is specified, a count of the number of queries
per second during the interval will be printed out every
stats_interval seconds.
-t timeout
Specifies the request timeout value, in seconds. dnsperf will no
longer wait for a response to a particular request after this
many seconds have elapsed. The default is 5 seconds.
-u
Instructs dnsperf to send DNS dynamic update messages, rather
than queries. The format of the input file is different in this
case; see the "Constructing a dynamic update input file" section
for more details.
-v
Enables verbose mode. The DNS RCODE of each response will be re‐
ported to standard output when the response is received, as will
the latency. If a query times out, it will be reported with the
special string "T" instead of a normal DNS RCODE. If a query is
interrupted, it will be reported with the special string "I".
-x local_port
Specifies the local port from which to send requests. The de‐
fault is the wildcard port (0).
If acting as multiple clients and the wildcard port is used,
each client will use a different random port. If a port is spec‐
ified, the clients will use a range of ports starting with the
specified one.
-y [alg:]name:secret
Add a TSIG record [RFC2845] to all packets sent, using the spec‐
ified TSIG key algorithm, name and secret, where the algorithm
defaults to hmac-md5 and the secret is expressed as a base-64
encoded string.
AUTHOR
Nominum, Inc.
SEE ALSOresperf(1)Nominum Jan 10, 2012 DNSPERF(1)
