Table of Contents
- Virtual User Generator (VuGen)
- Controller and Load Generator
- Result Analysis
- Common issues with Load Runner
HP Load Runner is a popular automated load and performance testing tool that emulates actual load to check the performance and behavior of a product. Load Runner comprises three important components namely Virtual User Generator (VuGen), Controller and Load Generator and Analysis.
In fact, before we start discussing the ‘common issues’, let’s take a moment to go through the main LoadRunner components in brief as this would make the terms used in this article more meaningful and clear.
Virtual User Generator (VuGen)
For load and performance testing, you need to create scripts for simulating transactions. That is what VUGen does, in fact, it is one of the most important and most frequently used components of LoadRunner. As a scripting tool, VuGen enables you to create specific user scripts that record various transactions. In addition to creating user scripts, VuGen allows the following tasks:
- VUGen allows you to record or develop scripts.
- Parametrize the scripts with data.
- You can add a checkpoint for test conditions.
- Allows for script debugging
- You can measure the transaction timings
Controller and Load Generator
The controller is responsible for executing scripts. When VuGen creates user scripts to simulate transactions, the next requirement is the creation of user case scenarios that simulate the behaviour of a user. These user cases or Vusers are executed and managed by the controller from a single workstation. In addition to passing scripts to the Load Generator which executes Vuser scripts, the controller collects the resulting information for analysis.
Result Analysis
HP Load Runner offers analytic tools that enable you to create detailed reports from Vuser logs generated after the execution of tests. You can either analyze reports from a single test or compare multiple tests.
Common issues with Load Runner
While HP Load Runner is a great tool to increase the quality of a product, technical issues can be frustrating as well. Here are some of the common issues experienced while working with Load Runner.
This is a common issue seen with most versions of LR. This issue is caused when you clean up the contents of the TEMP folder. Most of us use clean up tools that regularly clear up temporary files from the computer. Sometimes, you do it manually as well. With Windows OS, it is a common phenomenon that the original file is saved in the hard drive and a temporary copy is created in the temporary folder when you open any file.
So, when you clear contents of the temp folder while some VuGen scripts are open, the data is lost. When you save or compile the script, it fills the data with garbage.
To prevent this issue, do not clean up the system when you are working with VuGen scripts.
This is another known issue particularly with version VuGen 11.04. When you replay scripts, it either freezes or closes automatically. This is because a thumbnail value is enabled in the registry and you need to disable it. To do so :
There are several reasons for the web recording tool to stop recording. Here are few tips to try.
