HP LoadRunner VuGen Questions Bank: Q. 61 to 70
Learn “VuGen” Module of HP LoadRunner through FAQs:
Q. 61: How many methods are available in VuGen for updating several parameter types?
Following three parameter update methods are available:
1) Each Occurrence method: It instructs the Vuser to use a new value for each occurrence of the parameter. This is useful when the statements using a parameter are unrelated. For example, for random data, it may be useful to use a new value for each occurrence of the parameter.
2) Each Iteration method: It instructs the Vuser to use a new value for each script iteration. If a parameter appears in a script several
times, the Vuser uses the same value for all occurrences of the parameter, for the entire iteration. This is useful when the statements using a parameter are related.
3) Once method: It instructs the Vuser to update the parameter value only once during the scenario run. The Vuser uses the same parameter value for all occurrences and all iterations of the parameter. This type may be useful when working with dates and times.
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Q. 62: What is Simulation of File Type Parameters for LoadRunner users?
Once a File type parameter is created, we can use the File Parameter Simulator to simulate the parameter substitution in an actual scenario.
Simulator allows us to correct any wrong parameters before we run the script in the Controller.
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Q. 63: What is the purpose of correlating statements in VuGen?
VuGen provides “Correlated Query” feature for linking the statements by using the results of one statement as input for the other. Correlating statements are used for optimizing the Vuser scripts.The objective of correlating statements are:
1) To simplify or optimize the code: For example, if we perform a series of dependent queries one after another, the code tends to become very long. To reduce the size of the code, we can nest the queries, but in this process we lose the precision and the code becomes complex and difficult to understand. In such a situation, correlating the statements enables us to link the queries without nesting.
2) To generate dynamic data: Many applications and Web sites identify a session by the current date and time. When we try to replay a script, it will fail because the current time is different than the recorded time. Correlating the data enables us to save the dynamic data and use it throughout the scenario run.
3) To accommodate unique data records: Certain applications like databases require the use of unique values. A value that was unique during recording is no longer unique for script execution. Lt us take an example, wherein we record the process of opening a new bank account. Each new account is assigned a unique number which is unknown to the user. This account number is inserted into a table with a unique key constraint during recording. If we try to run the script as recorded, it tries to create an account with the recorded number, rather than a new unique number. An error will result because the account number already exists.
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Q. 64: What are the various types of C Vuser correlation functions?
Following three types of C Vuser correlation functions are used for correlating the statements for protocols which do not have any specific functions. These can be used to save a string to a parameter and retrieve it as and when required.
1) lr_eval_string Function: Replaces all occurrences of a parameter with its current value.
2) lr_save_string Function: Saves a null-terminated string to a parameter.
3) lr_save_var Function: Saves a variable length string to a parameter.
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Q. 65: What are the various types of Java Vuser correlation functions?
Following seven types of Java Vuser correlation functions are used . These can be used to save a string to a parameter and retrieve it as and when required.
1) lr.eval_string Function: Replaces a parameter with its current value.
2) lr.eval_data Function: Replaces a parameter with a byte value.
3) lr.eval_int Function: Replaces a parameter with an integer value.
4) lr.eval_string Function: Replaces a parameter with a string.
5) lr.save_data Function: Saves a byte as a parameter.
6) lr.save_int Function: Saves an integer as a parameter.
7) lr.save_string Function: Saves a null-terminated string to a parameter.
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Q. 66: What is the purpose of WDiff utility?
WDiff is a tool for determining which values to correlate. With the help of this we can compare recorded scripts and results to find out as to which values need to be correlated.
While working with other protocols, we can view the Execution log to find out where the script failed and then use the WDiff utility to help us in locating the values that need to be correlated.
For making an effective use of WDiff utility, we need to record the identical operation twice, and compare the scripts. It displays differences in yellow color.
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Q. 67: Why do we configure th run-time settings for Vuser Scripts?
After a Vuser script is recorded, we need to set its run-time settings to define the way the new script should run. These run-time settings get applied to the Vusers when a script is made to run through LoadRunner’s VuGen or Controller.
These run-time settings are stored in the “default.cfg” file, located in the Vuser script directory.
By defining the run-time settings we can emulate various types of user activity. For example, we can emulate a user who responds immediately to output from the server, or a user who stops and thinks before each response. We can use these run-time settings to specify how many times the Vuser should repeat its set of actions.
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Q. 68: What are Action Blocks in Scripts?
Action blocks are groups of actions within the script. We can create separate action blocks for groups of actions by adding the same action to several blocks. We can instruct VuGen to execute action blocks or individual actions sequentially or randomly.We can set the properties of each action block independently. These properties can be like the following:
1) Sequence: means the order of actions within your script.
2) Iterations: Means the number of times Vusers repeat all of the Actions.
3) Weighting:Means weight or percentage of each action within a block.
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Q. 69: What is the purpose of Pacing Run Time settings for multiple actions?
Pacing Run Time settings allows us to control the time between iterations. The pace tells the Vuser how long to wait between iterations of your actions. We can instruct the Vusers to start each iteration by either of the following methods:
1) As soon as the previous iteration ends: The new iteration begins as soon as possible after the previous iteration ends.
2) After the previous iteration ends with a fixed or random delay: It starts each new iteration a specified amount of time after the end of the previous iteration. Specify either an exact number of seconds or a range of time. For example, we can specify to begin a new iteration at any time between 60 and 90 seconds after the previous iteration ends.
3) At fixed or random intervals: We specify the time between iteration – either a fixed number of seconds or a range of seconds from the beginning of the previous iteration. For example, we can specify to begin a new iteration every 30 seconds, or at a random rate ranging from 30 to 45 seconds from the beginning of the previous iteration. Each scheduled iterations will only begin when the previous iteration is complete.
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Q. 70: How many type of information logging are available?
We can specify the type of information that is logged in following ways
1) Standard Log: Creates a standard log of functions and messages sent during script execution to use for debugging. Disable this option for large load testing scenarios or profiles.
2) Extended Log: Creates an extended log, including warnings and other messages. It is recommended to disable this option for large load testing scenarios or profiles.
Continue to Next Part : Q 71 to 80
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