Provided by: apache2-utils_2.4.29-1ubuntu4_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 ] [ -m HTTP-method ] [ -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 ] [http[s]://]hostname[:port]/path


       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, TLS1.1, TLS1.2, or ALL). TLS1.1 and
              TLS1.2 support available in 2.4.4 and later.

       -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
              useful for dynamic pages. Available in 2.4.7 and later.

       -m HTTP-method
              Custom HTTP method for the requests. Available in 2.4.10 and later.

       -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
              seconds. Available in 2.4.4 and later.

       -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.