When designing a set of performance tests it is necessary to consider pauses between user interactions. This is usually referred to as “think time”, and represents the time between the system presenting the results of an action and the next action being taken. If a load test script doesn’t include any think time at all then the system will be bombarded with requests at a rate that isn’t humanly possible. Depending on the system there are likely to be between 10 and 100 times the interactions generated with zero think time than with realistic scenarios. Continue reading ‘Do your users think?’ »
Posts tagged ‘modelling’
Let us assume that you have started a piece of performance modelling. You have chosen a set of key transactions, or better still have been told what is most important by the business. You may have an idea of the performance levels that the business need (more on this another time), and you start working with the business to work out the volumes that they are expecting to put through the system. To do the appropriate performance modelling you will need to define the behaviour of a “typical user” and then scale this up to produce a total behaviour profile for all users. It is unfortunate that you are unlikely to receive figures that can be used directly from your business users. You have the following choices at this point: a) educate them in the modelling you are doing and the format you need the numbers in, or b) take the numbers they have provided and reproduce them from your modelling. Continue reading ‘Business volumes and performance modelling’ »
A new computer system goes into production and starts with a pilot. A set of load testing is done to make sure that the live user levels can be supported, with some problems. These problems are resolved and maybe some extra hardware purchased to ensure performance at live volumes is acceptable, and then a full roll out is started. The project team are on site for the first few weeks, and resolve the problems that are experienced initially. The system is handed over to support along with a development team member and then the project team is disbanded. The support team are left to complete the roll out process, and the development team member moves on after a while. Continue reading ‘The case for predicting the future’ »
