HP LoadRunner Basics Questions: Q. 11 to 20
Learn Basic Introduction & preliminaries of HP LoadRunner through FAQs:
Q. 11: What is a correlation in LoadRunner?
Correlation is used to obtain data which are unique for each run of the script and which are generated by nested queries. Correlation provides the value to avoid errors arising out of duplicate values and also optimizing the code (to avoid nested queries).
Corelations are of two types like :
1) Automatic correlation iinvolves setting of some rules for thecorrelation. It can be application server specific. Here values are replaced by data which are created by these rules.
2) Manual correlation, the value we want to correlate is scanned and create correlation is used to correlate.
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Q. 12: How can we find out as to where correlation is required in LoadRunner?
There are two ways to find out the place of use of corelation
1) We can scan for correlations, and see the list of values which can be correlated. From this we can pick a value to be correlated.
2) We can record two scripts and compare them.
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Q. 13: Where can we set automatic correlation options in LoadRunner?
We can set the automatic correlation from web point of view in recording options and correlation tab. Here we can enable correlation for the entire script and choose either issue online messages or offline actions, where we can define rules for that correlation.
Automatic correlation for database can be done using show output window and scan for correlation and picking the correlate query tab and choose which query value we want to correlate. If we know the specific value to be correlated, we just do create correlation for the value and specify how the value to be created.
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Q. 14: What is the function to capture dynamic values in the web Vuser script in LoadRunner?
Web_reg_save_param function saves dynamic data information to a parameter.
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Q. 15: When do you disable log in Virtual User Generator in LoadRunner?
Once we debug our script and verify that it is functional, we can enable logging for errors only. When we add a script to a scenario, logging is automatically disabled.
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Q. 16: When do we use standard and extended logs in LoadRunner?
Standard Log Option: It creates a standard log of functions and messages sent during script execution to use for debugging.
It is suggested to disable this option for large load testing scenarios. When you copy a script to a scenario, logging is automatically disabled.
Extended Log Option: Is selected to create an extended log, including warnings and other messages. We can specify all additional information that needs to be added to the extended log.
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Q. 17: How do we debug a script in LoadRunner?
VuGen contains two options to help debug Vuser scripts-the Run Step by Step command and breakpoints.
The Debug settings in the Options dialog box allow us to determine the extent of the trace to be performed during scenario execution.
The debug information is written to the Output window. We can manually set the message class within our script using the lr_set_debug_message function. This is useful if we want to receive debug information about a small section of the script only.
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Q. 18:How do we write user defined functions in LoadRunner?
Before we create the User Defined functions we need to create the external library (DLL) with the function. We add this library to VuGen bin directory. Once the library is added then we assign user defined function as a parameter.
The function should have the following format: __declspec (dllexport) char* (char*, char). Few examples of user defined functions are GetVersion, GetCurrentTime, GetPltform etc.
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Q. 19: What are the changes possible to be made in run-time settings in LoadRunner?
The Run Time Settings are:
a) Pacing – Has iteration count.
b) Log – Needs to Disable the Logging Standard Log
c) Extended Think Time – In think time there are two options like Ignore think time and Replay think time.
d) General – Under general tab we can set the vusers as process or as multithreading and each step as a transaction.
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Q. 20: Where do we set Iterations for Vuser testing in LoadRunner?
Iterations are set in the Run Time Settings of the VuGen. The navigation for this is Run time settings, Pacing tab, set number of iterations.
Continue to Next Part : Q 21 to 30

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