Provided by: apache2-utils_2.4.7-1ubuntu4_amd64 bug


       ab - Apache HTTP server benchmarking tool


       ab [ -A auth-username:password ] [ -b windowsize ] [ -B local-address ] [ -c concurrency ]
       [ -C cookie-name=value ] [ -d ] [ -e csv-file ] [ -f protocol ] [ -g gnuplot-file ] [ -h ]
       [  -H  custom-header  ]  [ -i ] [ -k ] [ -l ] [ -n requests ] [ -p POST-file ] [ -P proxy-
       auth-username:password ] [ -q ] [ -r ] [ -s timeout ] [  -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

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

       -B local-address
              Address to bind to when making outgoing connections.

       -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 'binned'.

       -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.

       -l     Do not report errors if the length of the responses is not constant.  This  can  be
              usefull for dynamic pages.

       -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

       -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 timeout
              Maximum  number  of  seconds  to  wait  before  the socket times out. Default is 30

       -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

       -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 timelimit.

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

       -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 https.

       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 the size in bytes of the  first  successfully  returned  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 received

       Complete requests
              The number of successful responses received

       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 number 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 printed.

       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

       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 taken

       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.