What are different aspects of stress testing?

Stress testing can be defined as a form of testing that is carried out to determine the stability and the stress handling capacity of a software system or module. Stress testing is all about testing the software system or application beyond the normal operational capacities. It is the testing of software system or application to its breaking or fatal point. This is done in order to observe the results.

Stress testing has a much broader meaning. What is basically understood by a stress test?
- It is referred to a test that mainly focuses upon the availability, error handling and robustness of a software system or application.
- In stress testing the software system or application is subjected heavy loads of tasks.
- It is not about considering the proper behavior under the normal operational conditions or user environment.

Typically the goal of stress testing is to test whether or not the software system or application crashes or fails in the case of catastrophic problems like unavailability of sufficient computing resources. These computational resources may include disk space or memory. It is also done to determine if the system crashes or fails under the situation of denial of service attacks and unusually high concurrency.

Stress testing, load testing, volume testing all seem like much similar kinds of testing.

A look at the following examples of stress testing will clear up the confusions regarding stress testing:


- Stress testing for web server:
A web server can be subjected to stress testing using bots, scripts and several denial of service tools to determine its performance and behavior during the peak data and tasks load.

- Stress testing can be studied in contrast with load testing.
Load testing is basically carried out to examine the entire testing environment and the huge database. It is also carried out to determine the response time of the software system or application whereas the stress testing exclusively focuses upon identifying the transactions and pushing them to a level at which a break occurs in the execution of the transaction software system.

Another point is that during the stress testing if the transactions are duly stressed, then the chance is that the database may not experience a huge data load. However if the transactions are not stressed, the data base may experience a heavy work load.

SOME IMPORTANT POINTS:
- Stress testing is another word for system stress testing.
- It can be defined as the loading of the concurrent users beyond and over the level that can be handled by the system.
- This leads to the breakage of the weakest link in the whole software system or application.
- While carrying out the stress testing the software engineers, developers or testers need to test the whole software system or application under the desired expected stress as well as under the accelerated stress.
- The goal here is to determine the working life of the software system.
- It is also aimed at determining the modes of failure for the software system or application.
- For the hardware counterpart of a complete system, the stress testing can be defined as the subjecting of the concerned hardware to the exaggerated levels of stress.
- This is basically done to determine the stability of the hardware system when used in a normal environment rather than a testing environment.
- Before modifying the CPU parameters during the processes of over clocking, over volting, under volting and under clocking, it is necessary to verify whether or not the new CPU parameters like frequency and core voltage are suitable for taking the heavy CPU loads.
- Stress testing for such parameters is usually carried out by executing a CPU intensive program for a prolonged significant period of time. It is observed if the system crashes or hangs.