ab
ab(1) ab(1)
NAME
ab - Apache HTTP server benchmarking tool
SYNOPSIS
ab [ -k ] [ -e ] [ -q ] [ -S ] [ -i ] [ + .B -s ] [ -n requests ] [ -t
timelimit ] [ -c concurrency ] [ -p POST file ] [ -A Authentication
username:password ] [ -P Proxy Authentication username:password ] [ -H
Custom header ] [ -C Cookie name=value ] [ -T content-type ] [ -X proxy
[ :port ] ] [ -v verbosity ] ] [ -w output HTML ] ] [ -g output GNUPLOT
] ] [ -e output CSV ] ] [ -x <table> attributes ] ] [ -y <tr>
attributes ] ] [ -z <td> attributes ] [http[s]://]hostname[:port]/path
ab [ -V ] [ -h ]
DESCRIPTION
ab is a tool for benchmarking your Apache HyperText Transfer Protocol
(HTTP) server. It is designed to give you an impression of how your
current Apache installation performs. This especially shows you how
many requests per second your Apache installation is capable of serv-
ing.
OPTIONS
-k Enable the HTTP KeepAlive feature, i.e., perform multiple
requests within one HTTP session. Default is no KeepAlive.
-n requests Number of requests to perform for the benchmarking session.
The default is to just perform a single request which usu-
ally leads to non-representative benchmarking results.
-t timelimit
Maximum number of seconds to spend for benchmarking. This
implies -d Do not display the "percentage served within XX
[ms] table". (legacy support).
-S Do not display the median and standard deviation values,
nor display the warning/error messages when the average and
median are more than one or two times the standard devia-
tion apart. And default to the min/avg/max values. (legacy
support).
-s When compiled in (bb -h will show you) use the SSL pro-
tected https rather than the http protocol. This feature is
experimental and very rudimentary. You propably do not want
to use it.
-k Enable the HTTP KeepAlive feature; that is, perform multi-
ple requests within one HTTP session. Default is no
KeepAlive. a -n 50000 internally. Use this to benchmark
the server within a fixed total amount of time. Per
default there is no timelimit.
-c concurrency
Number of multiple requests to perform at a time. Default
is one request at a time.
-p POST file
File containing data to POST.
-A Authentication username:password
Supply BASIC Authentication credentials to the server. The
username and password are separated by a single ':' and
sent on the wire uuencoded. The string is sent regardless
of whether the server needs it; (i.e., has sent an 401
authentication needed).
-X proxy[:port]
Route all requests through the proxy (at optional port).
-P Proxy-Authentication username:password
Supply BASIC Authentication credentials to a proxy en-
route. The username and password are separated by a single
':' and sent on the wire uuencoded. The string is sent
regardless of whether the proxy needs it; (i.e., has sent
an 407 proxy authentication needed).
-C Cookie name=value
Add a 'Cookie:' line to the request. The argument is typi-
cally in the form of a 'name=value' pair. This field is
repeatable.
-p Header string
Append extra headers to the request. The argument is typi-
cally in the form of a valid header line, containing a
colon-separated field-value pair. (i.e., 'Accept-Encoding:
zip/zop;8bit').
-T content-type
Content-type header to use for POST data.
-g gnuplot file
Write all measured values out as a 'gnuplot' or TSV (Tab
separate values) file. This file can easily be imported
into packages like Gnuplot, IDL, Mathematica, Igor or even
Excell. The labels are on the first line of the file.
-q When processing more than 150 requsts; ab outputs a
progress count on stderr every 10% or 100 requests or so.
The -q flag qill suppress these messages.
-e CSV file Write a Comma separated value (CSV) file which contains for
each percentage (from 1% to 100%) the time (in milli sec-
onds) it took to serve that percentage of the requests.
This is usually more usefull than the 'gnuplot' file; as
the results are already
-v Set verbosity level - 4 and above prints information on
headers, 3 and above prints response codes (404, 200,
etc.), 2 and above prints warnings and info.
-w Print out results in HTML tables. Default table is two
columns wide, with a white background.
-x attributes
String to use as attributes for <table>. Attributes are
inserted <table here >
-y attributes
String to use as attributes for <tr>.
-z attributes
String to use as attributes for <td>.
-V Display version number and exit.
-h Display usage information.
BUGS
There are various statically declared buffers of fixed length. Combined
with the lazy parsing of the command line arguments, the response head-
ers from the server and other external inputs, this might bite you.
It does not implement HTTP/1.x fully; only accepts some 'expected'
forms of responses. The rather heavy use of strstr(3) shows up top in
profile, which might indicate a performance problem; i.e., you would
measure the ab performance rather than the server's.
SEE ALSO
httpd(8)
The HTML output is not as complete as the text output.
Up to version 1.3d ab has propably reported values way to low for most
measurements; as a single timeout (which is usually in the order of
seconds) will shift several thousands of milli-second responses by a
considerable factor. This was further componded by a serious interger
overrun which would for realistic run's (i.e. those longer than a few
minutes) produce believable but totally bogus results. Thanks to Sander
Temme <sander@covalent.net> for solving this riddle.
March 2000 ab(1)
