Web Load Testing
Web Load Testing involves checking how a website or service performs as the load on it (the number and volume of requests) is increased.
Why do web load testing?
A website needs to stay up under normal and expected load conditions, but in addition to that, the load will not remain constant, since there are several reasons why the number of requests might suddenly spike:
- Increased popularity of the website - This could happen very quickly, for example when a popular site links to yours (Digg and Slashdot effects). If your site is not able to cope with the sudden onrush of requests, it can render your site unusable.
- Denial of Service Attacks - This is what happens when somebody tries to bring down your site by making more requests than it can handle. The most common form is a Distributed denial of service attack, in which case numerous computers are used to make requests on the site at the same time.
Here are some things to keep in mind when creating Web LoadTests:
- Test the most common behaviour that you expect from the users first.
- Test behaviours that you expect will cause high loads (e.g. Operations that involve a lot of database access might fall into this category).
- Spend at least some of the time doing exploratory testing.