QA Tester Performance Testing

Question

How do I test how the software behaves if several users enter the web site? ex: for example 100 users

Answer 1

The most obvious way to test it is to actually have 100 people entering the website at the same time. Yet, if you do not have 100 people at your disposal, or you want to save costs, then you can implement a feature that automatically enters your site and call that 100 times.

You can do it with Selenium, or even a bash script which does cURL requests for you.

Yet, it's quite possible that "entering the website" is much more vague than the test you actually need to perform. If so, then try to narrow down to the problem-space that covers your interest in the most minimalistic way (not containing elements you do not need). For example, if you are interested in the performance of a function, then you do not need 100 users using the site, but 100 calls of that function.