Performance Testing

1.    Explain system testing.
System testing is performed to verify that a system meets the requirements specifications. It checks the behavior of the whole system, based on the defined scope. It is very common for system testing to be the last test that is performed by the development team before it is released.

2.    Explain the difference between regression testing and retesting.
Retesting is the running of tests that failed in the previous round of testing to verify that the corrective actions taken were successful in fixing the defects that were found. Regression testing, on the other hand, is checking a program after the modifications have been made to ensure that no new defects have been introduced into the system.

3.    What is a test suite?
A test suite is a set of test cases that is designed for a system or a component of software, where the result of each test is used as input to the next.

4.    Explain the difference between testing and debugging.
Testing can consist of both static and dynamic testing life cycle activities. It is used to determine that the software satisfies the requirements. Debugging, on the other hand, is the process of identifying, locating, and fixing a defect in a system or application.

5.    Explain the difference between load and volume testing.
Load testing is checking the behavior of a component or a system when the user or transaction load is increased. On the other hand, volume testing verifies that the system can handle a large amount of data, not necessarily a large number of users or transactions.

6.    What is the difference between functional and load testing?
Functional testing checks the functionality of the system or the application while load testing checks the stability, functionality, and performance of the system or application under load.

7.    What are some common tools used for load testing?

• Rational Performance Tester – IBM Rational
• LoadRunner – HP
• Silk Performer – Borland
• Open STA –Open Source tool
• QALoad – Compuware
• Neo Load – Neotys
• Web Load – Radview

8.    What is the difference between load and performance testing?

Load testing is performed to verify that the system can handle increased loads and to check the scalability of the application.  Performance testing is used check the system for proper performance. The performance is measured in terms of number of requests processed per second, response time, etc. Both load and performance testing can be used at the same time.

9.    Explain boundary analysis.

Boundary value analysis is a software testing technique where tests are designed for checking the boundary limits of the application. Test cases that are prepared for boundary value analysis are used to check bugs that may arise at the boundaries or just over the boundaries.  This design strategy typically used as a part of black box testing.

10. Explain performance baseline testing.

Performance testing typically begins with performance baseline testing and it is when a tester establishes a standard that will be used for the comparison of new or unknown measurements and performance. Performance baseline testing is sometimes referred to benchmark testing.

11. What types of bottlenecks are likely in performance testing?

Bottlenecks in performance testing slow down testing and can affect the performance and the scalability of an application.  Hardware, software, bandwidth that has defined limits in the flow of data, processing speed, and any of the system resources can create bottlenecks in a system.  Some of these bottlenecks include the following:

• Increased time
• Increased number of resources
• Appropriate monitors to determine performance