AB(8)                                 ab                                 AB(8)

       ab - Apache HTTP server benchmarking tool

       ab [ -A auth-username:password ] [ -b windowsize ] [ -c concurrency ] [
       -C cookie-name=value ] [ -d ] [ -e csv-file ] [ -f protocol ] [ -g
       gnuplot-file ] [ -h ] [ -H custom-header ] [ -i ] [ -k ] [ -n requests
       ] [ -p POST-file ] [ -P proxy-auth-username:password ] [ -q ] [ -r ] [
       -s ] [ -S ] [ -t timelimit ] [ -T content-type ] [ -u PUT-file ] [ -v
       verbosity] [ -V ] [ -w ] [ -x <table>-attributes ] [ -X proxy[:port] ]
       [ -y <tr>-attributes ] [ -z <td>-attributes ] [ -Z ciphersuite ]

       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

       -A auth-username:password
              Supply BASIC Authentication credentials to the server. The
              username and password are separated by a single : and sent on
              the wire base64 encoded. The string is sent regardless of
              whether the server needs it (i.e., has sent an 401
              authentication needed).

       -b windowsize
              Size of TCP send/receive buffer, in bytes.

       -c concurrency
              Number of multiple requests to perform at a time. Default is one
              request at a time.

       -C cookie-name=value
              Add a Cookie: line to the request. The argument is typically in
              the form of a name=value pair. This field is repeatable.

       -d     Do not display the "percentage served within XX [ms] table".
              (legacy support).

       -e csv-file
              Write a Comma separated value (CSV) file which contains for each
              percentage (from 1% to 100%) the time (in milliseconds) it took
              to serve that percentage of the requests. This is usually more
              useful than the 'gnuplot' file; as the results are already

       -f protocol
              Specify SSL/TLS protocol (SSL2, SSL3, TLS1, or ALL).

       -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.

       -h     Display usage information.

       -H custom-header
              Append extra headers to the request. The argument is typically
              in the form of a valid header line, containing a colon-separated
              field-value pair (i.e., "Accept-Encoding: zip/zop;8bit").

       -i     Do HEAD requests instead of GET.

       -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 usually leads
              to non-representative benchmarking results.

       -p POST-file
              File containing data to POST. Remember to also set -T.

       -P proxy-auth-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 base64 encoded. The string is sent regardless of
              whether the proxy needs it (i.e., has sent an 407 proxy
              authentication needed).

       -q     When processing more than 150 requests, ab outputs a progress
              count on stderr every 10% or 100 requests or so. The -q flag
              will suppress these messages.

       -r     Don't exit on socket receive errors.

       -s     When compiled in (ab -h will show you) use the SSL protected
              https rather than the http protocol. This feature is
              experimental and very rudimentary. You probably do not want to
              use it.

       -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 deviation apart. And
              default to the min/avg/max values. (legacy support).

       -t timelimit
              Maximum number of seconds to spend for benchmarking. This
              implies a -n 50000 internally. Use this to benchmark the server
              within a fixed total amount of time. Per default there is no

       -T content-type
              Content-type header to use for POST/PUT data, eg. application/x-
              www-form-urlencoded. Default: text/plain.

       -u PUT-file
              File containing data to PUT. Remember to also set -T.

       -v verbosity
              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.

       -V     Display version number and exit.

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

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

       -X proxy[:port]
              Use a proxy server for the requests.

       -y <tr>-attributes
              String to use as attributes for <tr>.

       -z <td>-attributes
              String to use as attributes for <td>.

       -Z ciphersuite
              Specify SSL/TLS cipher suite (See openssl ciphers).

       The following list describes the values returned by ab:

       Server Software
              The value, if any, returned in the server HTTP header of the
              first successful response. This includes all characters in the
              header from beginning to the point a character with decimal
              value of 32 (most notably: a space or CR/LF) is detected.

       Server Hostname
              The DNS or IP address given on the command line

       Server Port
              The port to which ab is connecting. If no port is given on the
              command line, this will default to 80 for http and 443 for

       SSL/TLS Protocol
              The protocol parameters negotiated between the client and
              server. This will only be printed if SSL is used.

       Document Path
              The request URI parsed from the command line string.

       Document Length
              This is size in bytes of the first succesfully returning
              document. If the document length changes during testing, the
              response is considered an error.

       Concurrency Level
              The number of concurrent clients used during the test

       Time taken for tests
              This is the time taken from the moment the first socket
              connection is created to the moment the last response is

       Complete requests
              The number of successful responses recieved

       Failed requests
              The number of requests that were considered a failure. If the
              number is greater than zero, another line will be printed
              showing the numer of requests that failed due to connecting,
              reading, incorrect content length, or exceptions.

       Write errors
              The number of errors that failed during write (broken pipe).

       Non-2xx responses
              The number of responses that were not in the 200 series of
              response codes. If all responses were 200, this field is not

       Keep-Alive requests
              The number of connections that resulted in Keep-Alive requests

       Total body sent
              If configured to send data as part of the test, this is the
              total number of bytes sent during the tests. This field is
              omitted if the test did not include a body to send.

       Total transferred
              The total number of bytes received from the server. This number
              is essentially the number of bytes sent over the wire.

       HTML transferred
              The total number of document bytes received from the server.
              This number excludes bytes received in HTTP headers

       Requests per second
              This is the number of requests per second. This value is the
              result of dividing the number of requests by the total time

       Time per request
              The average time spent per request. The first value is
              calculated with the formula concurrency * timetaken * 1000 /
              done while the second value is calculated with the formula
              timetaken * 1000 / done

       Transfer rate
              The rate of transfer as calculated by the formula totalread /
              1024 / timetaken

       There are various statically declared buffers of fixed length. Combined
       with the lazy parsing of the command line arguments, the response
       headers 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.

Apache HTTP Server                2012-04-09                             AB(8)