WHAT IS IT?
Siege is an open source regression test and benchmark utility.
It can stress test a single URL with a user defined number of
simulated users, or it can read many URLs into memory and
stress them simultaneously. The program reports the total
number of hits recorded, bytes transferred, response time,
concurrency, and return status. Siege supports HTTP/1.0 and 1.1
protocols, the GET and POST directives, cookies, transaction
logging, and basic authentication. Its features are configurable
on a per user basis.
Most features are configurable with command line options which
also include default values to minimize the complexity of the
program's invocation. Siege allows you to stress a web server
with n number of users t number of times, where n and t are
defined by the user. It records the duration time of the test
as well as the duration of each single transaction. It reports
the number of transactions, elapsed time, bytes transferred,
response time, transaction rate, concurrency and the number of
times the server responded OK, that is status code 200.
Siege was designed and implemented by Jeffrey Fulmer in his
position as Webmaster for Armstrong World Industries. It was
modeled in part after Lincoln Stein's torture.pl and it's data
reporting is almost identical. But torture.pl does not allow
one to stress many URLs simultaneously; out of that need siege
When a HTTP server is being hit by the program, it is said to be
WHY DO I NEED IT?
Siege was written for both web developers and web systems admin-
istrators. It allows those individuals to test their programs
and their systems under duress. As a web professional, you are
responsible for the intregrity of your product, yet you have no
control over who accesses it. Traffic spikes can occur at any
moment. How do you know if you're prepared?
Siege will allow you to place those programs under duress, to
allow you to better understand the load that they can with
stand. You'll sleep better knowing your site can withstand the
weight of 400 simultaneous transactions if your site currently
peaks at 250.
A transaction is characterized by the server opening a socket
for the client, handling a request, serving data over the wire
and closing the socket upon completion. It is important to note
that HUMAN internet users take time to digest the data which
comes back to them. Siege users do not. In practice I've found
that 400 simultaneous siege users translates to at least five
times that amount in real internet sessions. This is why siege
allows you to set a delay ( --delay=NUM ). When set, each siege
user sleeps for a random number of seconds between 1 and NUM.
Through your server logs you should be able to get the average
amount of time spent on a page. It is recommended that you use
that number for your delay when simulating internet activity.
WHERE IS IT?
The latest version of siege can be obtained via anonymous FTP:
The source repository is located on GitHub:
git clone https://github.com/JoeDog/siege.git
You can view in your browser here:
Updates and announcements are distributed via JoeBlog:
Siege was built with GNU autoconf. If you are familiar with
GNU software, then you should be comfortable installing siege
Please consult the file INSTALL for more details.
To enable HTTPS support, you will need openssl installed on
your system. http://www.openssl.org. For complete installation
instructions, see section 2 of INSTALL.
Documentation is available in man pages siege(1) layingsiege(1)
An html manual is included with this distribution: manual.html
Complete documentation for siege can be found at www.joedog.org
Consult the file COPYING for complete license information.
Copyright (C) 2000-2009 by Jeffrey Fulmer <email@example.com>
Permission is granted to anyone to make or distribute verbatim
copies of this document as received, in any medium, provided
that the copyright notice and this permission notice are
preserved, thus giving the recipient permission to redistribute
Permission is granted to distribute modified versions of this
document, or of portions of it, under the above conditions,
provided also that they carry prominent notices stating who last
In addition, as a special exception, the copyright holders give
permission to link the code of portions of this program with the
OpenSSL library under certain conditions as described in each
individual source file, and distribute linked combinations
including the two.
You must obey the GNU General Public License in all respects
for all of the code used other than OpenSSL. If you modify
file(s) with this exception, you may extend this exception to
your version of the file(s), but you are not obligated to do so.
If you do not wish to do so, delete this exception statement
from your version. If you delete this exception statement from
all source files in the program, then also delete it here.