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ab(8)





NAME

       ab - Apache HTTP server benchmarking tool


SYNOPSIS

       ab [ -k ] [ -e ] [ -q ] [ -S ] [ -i ] [ -s ] [ -n requests ] [ -t time-
       limit ] [ -c concurrency ] [ -p POST file ]  [  -A  Authenticate  user-
       name:password  ]  [  -X proxy [ :port ] ] [ -P Proxy Authenticate user-
       name:password ] [ -H Custom header ] [ -C Cookie name=value ] [ -T con-
       tent-type ] [ -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 the performance of your Apache HyperText
       Transfer Protocol (HTTP) server.  It does this by giving you an indica-
       tion  of  how  many  requests  per  second your Apache installation can
       serve.


OPTIONS

       -k          Enable the HTTP KeepAlive feature; that is, perform  multi-
                   ple  requests  within  one  HTTP  session.  Default  is  no
                   KeepAlive.

       -d          Do not display the "percentage served within  XX  [ms]  ta-
                   ble". (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  (ab  -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.  -i Use  an  HTTP  'HEAD'  instead  of  the  GET
                   method. Cannot be mixed with POST.

       -n requests The number of requests to perform for the benchmarking ses-
                   sion.  The default is to perform just one  single  request,
                   which will not give representative benchmarking results.

       -t timelimit
                   The  number  of  seconds  to spend benchmarking. Using this
                   option automatically set the number  of  requests  for  the
                   benchmarking  session  to 50000.  Use this to benchmark the
                   server for a fixed period of time.  By default, there is no
                   timelimit.

       -c concurrency
                   The number of simultaneous requests to perform. The default
                   is to perform one HTTP request at at time, that is, no con-
                   currency.

       -p POST file
                   A  file  containing  data that the program will send to the
                   Apache server in any HTTP POST requests.

       -A Authorization username:password
                   Supply Basic Authentication credentials to the server.  The
                   username  and  password  are separated by a single ':', and
                   sent as uuencoded data.  The string is sent  regardless  of
                   whether  the  server  needs  it;  that  is,  has sent a 401
                   Authentication needed.

       -X proxy[:port]
                   Route all requests through the proxy (at optional port).

       -P Proxy-Authorization username:password
                   Supply Basic Authentication  credentials  to  a  proxy  en-
                   route.  The username and password are separated by a single
                   ':', and sent  as  uuencoded  data.   The  string  is  sent
                   regardless of whether the proxy needs it; that is, has sent
                   a 407 Proxy authentication needed.

       -C Cookie name=value
                   Add a 'Cookie:' line to the request. The argument is  typi-
                   cally a 'name=value' pair. This option may be repeated.

       -p Header string
                   Append  extra headers to the request. The argument is typi-
                   cally in the form of a valid header line, usually  a  colon
                   separated  field value pair, for example, 'Accept-Encoding:
                   zip/zop;8bit'.

       -T content-type
                   The 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
                   Excel. 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          Sets  the verbosity level.  Level 4 and above prints infor-
                   mation on headers, level 3 and above prints response  codes
                   (for example, 404, 200), and level 2 and above prints warn-
                   ings and informational messages.

       -w          Print out results in HTML tables.  The default table is two
                   columns wide, with a white background.

       -x attributes
                   The  string  to  use as attributes for <table>.  Attributes
                   are inserted <table here >

       -y attributes
                   The string to use as attributes for <tr>.

       -z attributes
                   The string to use as attributes for <td>.

       -V          Display the version number and exit.

       -h          Display usage information.


BUGS

       There are various statically declared buffers of fixed length. Combined
       with  inefficient  parsing  of the command line arguments, the response
       headers from the server, and other external inputs, these buffers might
       overflow.

       Ab  does  not  implement  HTTP/1.x fully; instead, it only accepts some
       'expected' forms of responses.

       The rather heavy use of strstr(3) by the program may  skew  performance
       results,  since it uses significant CPU resources.  Make sure that per-
       formance limits are not  hit  by  ab  before  your  server's  limit  is
       reached.

       The HTML output is not as complete as the text output.

       Up to version 1.3d ab has propably reported values way too low for most
       measurements; as a single timeout (which is usually  in  the  order  of
       seconds)  will  shift  several  thousands of millisecond responses by a
       considerable factor. This was further componded by  a  serious  integer
       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 for solving this riddle.


SEE ALSO

       httpd(8)

                                 February 2004                           ab(8)

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