Understand the Performance Validation Tool-HP LoadRunner
Why do the organizations need a tool like LoadRunner:
When a multi-user enterprise application is being deployed, no organization can think of taking risk of failure or inefficient performance thereby affecting the enterprise wide efficiency on one hand and damaging its reputation on the other.
LoadRunner is a well-known performance verification & validation tool designed for making accurate predictions of the actual performance and behavior of the application, thereby increasing our confidence in the reliability of the new system before it gets actually deployed.
LoadRunner is a performance validation tool especially created to readily provide answer to questions like:
1) Whether my application is able to handle the expected user load and more?
2) Whether my application is able to handle the number of transactions required by the business?
3) Whether my application is amply stable under expected and unexpected user loads?
Modus operandi of LoadRunner:
In real world scenario, it is not possible to create situation involving say one thousand users using a system simultaneously so as to test the behavior of the system under such stressful conditions. LoadRunner can create such a situation.
LoadRunner artificially simulates several thousand users (which are called Virtual Users). These artificial / digitally created users are simultaneously forced to operate on the same task, thereby loading the system in a way it is expected to be loaded by real human users in actual practice.
With LoadRunner we can simulate situation with hundreds or thousands of artificial users & we can impose definite, consistent and repeatable loads on the system thereby stressing it from end-to-end. This way we can emulate several business processes & production conditions, which a deployed application is going to encounter.
Major components of LoadRunner:
Load Runner has following three major components for building and running the tests.
1) Virtual user generator (VuGen): For capturing the end-user business processes into automated scripts.
2) Controller: For organizing, driving, managing and monitoring the load.
3) Analysis: The analysis engine for viewing, analyzing / interpreting and comparing the results.
Key Benefits of LoadRunner:
1) Increase in confidence level related to performance of the new system.
2) Decreased risk of failure of the new Multi-user system under heavy loads.
3) Provides an absolutely clear view of end-to-end performance of the system before it goes live.
4) Verifies & confirms that the new application meets all the specified requirements related to performance.
5) Verifies & reduces problems during the product development lifecycle.
6) Greatly simplified process of script making at the user-interface level due to the use of Visual Scripting Language and ActiveScreen technology.
7) Ease of analysis due to AutoCorrelation wizard which automatically digests all the monitoring and diagnostics data and calculates the top five causes of performance degradation.
8) Easily integrates with latest J2EE, Microsoft Visual Studio and Microsoft .NET environments.
9) Helpful in precisely predicting the scalability and capacity of application; thereby optimizing the investments in hardware.
10) Higher scalability with limited hardware due to low requirement of CPU and memory resources per virtual user.
11) Helpful in precisely pointing out user level, code-level and system-level problems easily & quickly.
12) Helpful in minimizing the cost of defect removal due to thorough testing of the application well in advance during the development life cycle.
13) Helpful in creating an efficient service-level management well before the services go live.
14) Helpful in involving the developers in the performance testing efforts right from the beginning due to ease of use of LoadRunner scripts directly within the IDE.
15) Helpful in real-time performance monitoring of all the system components.
16) New feature Service-oriented architecture (SOA) Script Generator wizard helps in selecting testing aspects of SOA environments and creating scripts accordingly. Helpful in boundary testing, interoperability and security-related testing.
17) New feature of XML (Extensible Markup Language) parameter support, having a facility of replacing the complete XML structure with a single parameter.