testing your webserver with siege

First, you’ll need to untar the package:
$ tar xvzf siege-latest.tar.gz

Then you’ll need to configure it; the default configuration is a good start:
$ ./configure

Configuration help is available with the -help suffix. The only one that I've personally added on is SSL support through the -with-ssl=/usr/local/ssl suffix.

Next, it’s time to compile and install:
$ make
$ make install

Laying Siege
Siege has a lot of options for how to "lay siege" against a Web server. The simplest and easiest way to get a feel for the program is to do a test against a single URL. The single URL test is also a good indication of how a particular page will hold up against a slashdot effect or other similar massive traffic driver.

Two critical options that need to be set are the number of concurrent users (-c, default is 10) and the duration of the test in terms of either repetitive queries or time (-t). Let’s start with a simple example of 25 concurrent users for one minute.
$ siege -c25 -t1M www.example.com
** Siege 2.59
** Preparing 25 concurrent users for battle.
The server is now under siege...
Lifting the server siege... done.
Transactions: 406 hits
Availability: 99.75 %
Elapsed time: 59.66 secs
Data transferred: 10340918 bytes
Response time: 2.36 secs
Transaction rate: 6.81 trans/sec
Throughput: 173330.84 bytes/sec
Concurrency: 16.07
Successful transactions: 412
Failed transactions: 1

Cradit : http://builder.com.com/5100-6371_14-5171727.html