2 Performance
2.1 Definitions
2.1.1 Performance
In the computer science is performance as a general term for the performance of a system which hardware, software or even a single algorithm can be used. Just as the components can be so different are the possible parameters for the determination of performance can be used.
Often the data throughput as the key parameters, ie as a measure of performance is the amount of data in a given time are processed relevant. This is true for example, writing and reading devices.
For Web applications are other important parameters. The decisive criterion is the amount of time a user must wait until it is the result of his request. This response time is made up of several parts.
Response time = browser response time + network response time + server response time
The response time can deal with a large number of users simultaneously processed increase as network response times and server response times by high load rise.
As a measure of the performance of a system must not only see the response time to be alone but always in connection with the number of users simultaneously processed be seen.
But ultimately it remains every themselves what level of abstraction he chooses, to the requirement for a system to define and what parameters he needs to evaluate.
2.1.2 Load test
Load tests are carried out in software projects, in which a user load is expected, the behavior of the system. A load test creates a high system load, either by simulation of many concurrent users or by quick repetition of processes or a user actions produced. Last tests over a longer period. During these tests are the times, and the system for the user requests is required, with a fixed number of users in parallel to the system actually is respected. Through these tests, the reliability of the system. In addition, the results as proof of compliance or non-compliance with non-functional dependencies are used.
2.1.3 Stress testing
In contrast to load testinh when there is no stress test fixed maximum number of parallel users, but the system will be tested to its limits. The burden in a short period of time as long as increases until functional error or a defined performance permanently limit is exceeded.
2.1.4 Benchmark testing
In benchmark tests is benchmarked with the performance of CPUs, electronic components and equipment and software application and boundary with the help of an evaluation programme to be examined. It is a benchmark to compare the performance of different data processing plants. To their comparability not on the opposition purely technical performance specifications to limit, by benchmark process lead time of several jobs, especially in the multiprocessing, measured and assessed.[4]
Translated by Yahoo Babelfish Service
