The first method is external load/stress testing – great solution for commercial projects. But there is also another good way for Apache – it’s open-source and free, called ApacheBench. It’s incredibly easy to use:

#ab -c10 -n3000 http://www.fastmonitoring.com/

• ab the name of the program
• C10 means the number of threads
• n3000 is the number of requests.

The program has a great variety of additional parameters — just check the official documentation. You can use cookies, POST requests, modified headers — everything that will help to simulate server users activity.

The program output is quite comprehensive:

Document Path:          /
Document Length:        121779 bytes
Concurrency Level:      10
Time taken for tests:   211.255212 seconds
Complete requests:      3000
Failed requests:        0
Write errors:           0
Total transferred:      63177000 bytes
HTML transferred:       63171000 bytes
Requests per second:    10.41 [#/sec] (mean)
Time per request:       480.425 [ms] (mean)
Time per request:       96.085 [ms] (mean, across all concurrent requests)
Transfer rate:          226.23 [Kbytes/sec] received
Connection Times (ms)
min  mean[+/-sd] median   max
Connect:        0    0   0.5      0      19
Processing:   181  479 186.0    444    1822
Waiting:      166  461 184.7    427    1708
Total:        181  479 186.0    444    1822
Percentage of the requests served within a certain time (ms)
50%    444
66%    525
75%    577
80%    619
90%    732
95%    819
98%    946
99%   1012
100%   1822 (longest request)

Highly recommended.