NAME
siege - An HTTP/HTTPS stress tester
INTRODUCTION
Siege is a multi-threaded http load testing and benchmarking utility.
It was designed to let web developers measure the performance of their
code under duress. It allows one to hit a web server with a
configurable number of concurrent simulated users. Those users place
the webserver "under siege." Performance measures include elapsed
time, total data transferred, server response time, its transaction
rate, its throughput, its concurrency and the number of times it
returned OK. These measures are quantified and reported at the end of
each run. Their meaning and significance is discussed below. Siege
has essentially three modes of operation: regression (when invoked by
bombardment), internet simulation and brute force.
INVOCATION
The format for invoking siege is: siege [options]
siege [options] [url]
siege -g [url]
Siege supports the following command line options:
-V, --version
VERSION, prints the version number
-h, --help
HELP, prints the help section which includes a summary of all
the command line options.
-C, --config
CONFIGURATION, prints the current configuration in the
$HOME/.siegerc file. Edit that file to set flag values for
EVERY siege run, a feature which eases runtime invocation. You
set an alternative resource file with the SIEGERC environment
variable: export SIEGERC=/home/jeff/haha
-v, --verbose
VERBOSE, prints the HTTP return status and the GET request to
the screen. Useful when reading a series of URLs from a
configuration file. This flag allows you to witness the
progress of the test.
-g, --get
GET, pull down headers from the server and display HTTP
transaction. Great for web application debugging. Requires a URL
be passed to siege on the command line.
-c NUM, --concurrent=NUM
CONCURRENT, allows you to set the concurrent number of simulated
users to num. The number of simulated users is limited to the
resources on the computer running siege.
-i, --internet
INTERNET, generates user simulation by randomly hitting the URLs
read from the urls.txt file. This option is viable only with
the urls.txt file.
-d NUM, --delay=NUM
DELAY, each siege simulated users sleeps for a random interval
in seconds between 0 and NUM.
-b, --benchmark
BENCHMARK, runs the test with NO DELAY for throughput
benchmarking. By default each simulated user is invoked with at
least a one second delay. This option removes that delay. It is
not recommended that you use this option while load testing.
-r NUM, --reps=NUM, --reps=once
REPS, allows you to run the siege for NUM repetitions. If
--reps=once, then siege will run through the urls.txt file one
time and stop when it reaches the end. NOTE: -t/--time takes
precedent over -r/--reps. If you want to use this option, make
sure time = x is commented out in your $HOME/.siegerc file.
-t NUMm, --time=NUMm
TIME, allows you to run the test for a selected period of time.
The format is "NUMm", where NUM is a time unit and the "m"
modifier is either S, M, or H for seconds, minutes and hours.
To run siege for an hour, you could select any one of the
following combinations: -t3600S, -t60M, -t1H. The modifier is
not case sensitive, but it does require no space between the
number and itself.
-l, --log
LOG, log stats to SIEGE_HOME/var/siege.log. If you’ve installed
siege in /usr/local, then the siege.log is
/usr/local/var/siege.log. This option logs the final statistics
reported when siege successfully completes its test. You can
edit $HOME/.siegerc to change the location of the siege.log
file.
-m MESSAGE, --mark=MESSAGE
MARK, mark the log file with a separator. This option will
allow you to separate your log file entries with header
information. This is especially useful when testing two
different servers. It is not necessary to use both the -m
option and the -l option. -m assumes -l so it marks and logs
the transaction. If the MESSAGE has spaces in it, make sure that
you put it in quotes.
-H HEADER, --header=HEADER
HEADER, this option allows you to add additional header
information.
-R SIEGERC, --rc=SIEGERC
RC, sets the siegerc file for the run. This option overrides the
environment variable SIEGERC and the default resource file,
$HOME/.siegerc
-f FILE, --file=FILE
FILE, the default URL file is SIEGE_HOME/etc/urls.txt. To
select a different URL file, use this option, i.e., siege -f
myurls.txt
-A "User Agent", --user-agent="User Agent"
AGENT, use this option to set the User-Agent in the request.
URL FORMAT
Siege understands the following URL formats:
(brackets indicate the directive is optional)
.br [protocol://] host.domain.xxx [:port] [/path/file]
.br host.domain.xxx/file POST field=value&field2=value2
.br Or you can POST the contents of a file using the line input
operator, the "<" character:
.br host/file POST </home/jeff/haha.txt
.br The first example above is an implicit GET, the next two are
obviously POSTs. You can pass parameters using GET much like you would
in a web browser:
www.haha.com/form.jsp?first=homer&last=simpson
.br If you invoke the URL as a command line argument, you should
probably place it in quotes. Currently, it supports two protocols,
http and https. If a protocol is not specified, then siege assumes
http. The minimum URL requirement is this: servername. That’s it. So
if you’re in the same domain as a server named shemp and shemp is in
your host file or it is in DNS, then: "siege shemp" will stress
http://shemp.yourdomain.net/index.html (assuming that "index.html" is
the server specified index). To stress the same page using https
protocol, the minimum URL requirement is this: https://shemp. That URL
specification will lay siege to https://shemp.yourdomain.net/index.html
URLS FILE
To hit multiple URLs, place them in a single file. The default URLs
file is $SIEGE_HOME/etc/urls.txt. [You may change that file with the
-f option, see above.] In that file list the URLs one per line:
# place all your comments behind hashes
http://homer.whoohoo.com/index.html
http://homer.whoohoo.com/howto.jsp
http://go.whoohoo.com/cgi-bin/q.cgi?scope=a
http://go.whoohoo.com/cgi-bin/q.cgi POST scope=a
http://homer.whoohoo.com/my.jsp POST a=1&b=2
# POST the contents of a file...
www.haha.com/aha.jsp POST </home/jeff/my.txt
www.haha.com/parser.jsp POST <./my.txt
When invoked without a URL on the command line, siege looks for URLs in
a file. Normally, it reads them all into memory and runs through them
sequentially. If you specify internet mode [-i], then it randomly
selects URLs to hit.
You may set and reference variables in URLs file. It is necessary to
set them PRIOR to referencing them. The syntax for defining variables
is NAME = VALUE with a single assignment on a single line. If you
define several variables in the file, you must place each assignment on
a single line. To use the value of the variable, you must reference it
inside $() or ${}, i.e., $(NAME). If you reference a variable that
doesn’t exist, siege will evaluate it to the empty string "".
# Example using variable assignment
# in the urls.txt file.
HOST = homer.whoohoo.com
http://${HOST}/index.html
http://${HOST}/howto.jsp
PERFORMANCE STATISTICS
Performance measures include elapsed time of the test, the amount of
data transferred ( including headers ), the response time of the
server, its transaction rate, its throughput, its concurrency and the
number of times it returned OK. These measures are quantified and
reported at the end of each run. The reporting format is modeled after
Lincoln Stein’s torture.pl script:
** Siege 2.60
** Preparing 100 concurrent users for battle.
The server is now under siege...done
Transactions: 339 hits
Availability: 93.39 %
Elapsed time: 67.47 secs
Data transferred: 4273708 bytes
Response time: 8.25 secs
Transaction rate: 5.02 trans/sec
Throughput: 63342.34 bytes/sec
Concurrency: 41.47
Successful transactions: 337
Failed transactions: 26
Longest transaction: 17.77 secs
Shortest transaction: 0.37 secs
Transactions
The number of server hits. In the example, 25 simulated users [
-c25 ] each hit the server 10 times [ -r10 ], a total of 250
transactions. It is possible for the number of transactions to
exceed the number of hits that were scheduled. Siege counts
every server hit a transaction, which means redirections and
authentication challenges count as two hits, not one. With this
regard, siege follows the HTTP specification and it mimics
browser behavior.
Availability
This is the percentage of socket connections successfully
handled by the server. It is the result of socket failures
(including timeouts) divided by the sum of all connection
attempts. This number does not include 400 and 500 level server
errors which are recorded in "Failed transactions" described
below.
Elapsed time
The duration of the entire siege test. This is measured from
the time the user invokes siege until the last simulated user
completes its transactions. Shown above, the test took 14.67
seconds to complete.
Data transferred
The sum of data transferred to every siege simulated user. It
includes the header information as well as content. Because it
includes header information, the number reported by siege will
be larger then the number reported by the server. In internet
mode, which hits random URLs in a configuration file, this
number is expected to vary from run to run.
Response time
The average time it took to respond to each simulated user’s
requests.
Transaction rate
The average number of transactions the server was able to handle
per second, in a nutshell: transactions divided by elapsed time.
Throughput
The average number of bytes transferred every second from the
server to all the simulated users.
Concurrency
The average number of simultaneous connections, a number which
rises as server performance decreases.
Successful transactions
The number of times the server responded with a return code <
400.
Failed transactions
The number of times the server responded with a return code >=
400 plus the sum of all failed socket transactions which
includes socket timeouts.
Longest transaction
The greatest amount of time that any single transaction took,
out of all transactions.
Shortest transaction
The smallest amount of time that any single transaction took,
out of all transactions.
AUTHOR
Jeffrey Fulmer, et al. <jeff@joedog.org>
BUGS
Report bugs to jeff@joedog.org. Give a detailed description of the
problem and report the version of siege that you are using.
COPYRIGHT
Copyright © 2000 2001 2004 Jeffrey Fulmer, et al.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
675 Mass Ave, Cambridge, MA 02139, USA.
AVAILABILITY
The most recent released version of siege is available by anonymous FTP
from ftp.joedog.org in the directory pub/siege.
SEE ALSO
siege.config(1) urls_txt(5) layingsiege(7)