Siege este un program pentru stress-ul si testarea performantei unui server http.

Exemplu de utilizare :
$ siege -u http://www.unixro.net -t 30s -d 20 -c 5
** siege 2.64
** Preparing 5 concurrent users for battle.
The server is now under siege...
HTTP/1.1 200 0.33 secs: 17015 bytes ==> /
...
Lifting the server siege... done.
Transactions: 18 hits
Availability: 100.00 %
Elapsed time: 30.33 secs
Data transferred: 0.29 MB
Response time: 0.23 secs
Transaction rate: 0.59 trans/sec
Throughput: 0.01 MB/sec
Concurrency: 0.14
Successful transactions: 18
Failed transactions: 0
Longest transaction: 0.33
Shortest transaction: 0.22

In cazul dat au fost realizate 5 cereri paralele, timp de 30 de secunde, cu intervalul intre cereri nu mai mare de 20 secunde.