Testing beyond the limits

What are your system’s limits, and what happens when you go beyond them? Part of the feature specification is to identify system limits and what values you are required to support. These can be difficult to judge, especially around loading. Having thousands of visitors a second to your website might be a problem you would love to have but, as a tester, it is your job to find out how well you can expect your site to perform.

System limits are of two types – policed and unpoliced. A policed limit is one in which the system actively blocks users from going beyond it. For instance, it might support 4 simultaneous players or a maximum group size of 20 users. You cannot configure the 5th player or the 21st user. That’s as opposed to unpoliced limits. System rates are typically of this kind: how many connections per second can you handle? Some configuration limits may also be unpoliced, such as the total number of users on the system, since...