I'm currently on a coldfusion VPS plan and want to know how many users my website can handle before I need to move to a dedicated server. Has anyone tried load testing on a VPS?
What are some of the free load testing tools?

You could try ab ( http://httpd.apache.org/docs/2.0/programs/ab.html ). If you have a linux server anywhere, install the apache-tools (or httpd-tools, dependent on distro) package, then run:
ab -n <number of requests to make> -c <# of simultaneous requests> <locationofpagetotest>

And this will send n number of requests, doing c number at a time, and tell you how quickly it was able to serve the pages. Example output:

Server Software: Apache/2.2.3
Server Hostname: <withheld>
Server Port: 80

Document Path: /
Document Length: 52688 bytes

Concurrency Level: 5
Time taken for tests: 10.303980 seconds
Complete requests: 200
Failed requests: 198
(Connect: 0, Length: 198, Exceptions: 0)
Write errors: 0
Total transferred: 10619093 bytes
HTML transferred: 10531293 bytes
Requests per second: 19.41 [#/sec] (mean)
Time per request: 257.599 [ms] (mean)
Time per request: 51.520 [ms] (mean, across all concurrent requests)
Transfer rate: 1006.41 [Kbytes/sec] received

Connection Times (ms)
min mean[+/-sd] median max
Connect: 26 27 0.4 27 29
Processing: 138 224 113.7 202 727
Waiting: 45 49 6.0 47 72
Total: 165 251 113.8 229 754

Percentage of the requests served within a certain time (ms)
50% 229
66% 241
75% 258
80% 265
90% 407
95% 523
98% 636
99% 751
100% 754 (longest request)


You could do this from any linux install, the server running the site can be any OS, in fact it would be better if you didn't run the test from the server itself.

Thanks dbodner. Unfortunately I dont have access to a linux server currently. Anyone know of any windows based load testing tools?

Hi Marcus,

I found a couple of open source software programs that should give you what you are looking for:

http://www.opensourcetesting.org/performance.php

http://jobmanager.sourceforge.net/openware_pub/loadsim/index.html