Performance Modelling
What is performance modelling?
- In A Level Computer Science, performance modelling is when the behaviour of something is tested or simulated before it is used in the real world
- It is a systematic approach that can be used for evaluating and predicting the performance characteristics of a software system
Using performance modelling in software production
- Performance modelling can be used to help understand how the software will behave under different load conditions and configurations
- It uses various metrics like response time and throughput to identify potential bottlenecks which can be used by developers to address performance issues before they affect end-users
- It can be integrated into various stages of the software development including the:
- Design phase to make architectural decisions
- Testing phase to simulate real world scenarios and measure the software’s performance
| Benefits | Drawbacks |
|---|---|
| Stress testing can ensure a system can cope with a large set of data or a large number of users. | The outcome of performance modelling is only as useful as the accuracy of the data that is fed into it. |
| You are able to predict problems and act on them before the problems actually occur in the real world. | If the rules that made up the model are wrong then it will produce incorrect results. |
Examples of performance modelling
Database optimisation
- Performance modelling can be used to simulate different database architectures and query strategies to find the most efficient setup
- It can help select the best indexing strategy and estimate the query response times under varying loads
- It may help decide between a relational database design or a single table design
Caching mechanisms
- By modelling how different caching strategies perform under various scenarios, optimal cache sizes can be determined
- Developers can assess the hit/miss ratio of caches and the latency improvements gained through caching
Use of performance modelling to determine a caching mechanism
Energy efficiency
- For mobile or embedded systems, performance modelling can be used to estimate power consumption under different usage patterns
- It can be useful for battery-powered devices where power consumption is a critical factor