Basic Knowledge of Game Testing

To be a game tester, you need to be an avid game player. But playing games is not enough, you need to have a flair for finding problems. A computer game is further complex than a usual software application. Mostly games are made up of collection of essential components like rendering engine, database, animations, sounds, special effects etc.

The process and techniques that are normally used for software testing will also be functional for Game Testing e.g. Code Inspection, Path and Flow testing, Incremental Focus Testing etc.

You have to examine each and every part of the game. For example

1. The tester must search and explore the game as much as possible.

2. Menus in the game and their functions.

3. Sounds and the sound effects in the game e.g. music, lip sync and sound in conjunction with animation sequence. 

4. Logic of the game and game flow.

5. Objects in the game - terrain, world, texture etc.

6. Frame rate of the animation etc.

7. Scoring in the game.

8. Camera view, Zoom in, Zoom out, replay etc.

9. Attributes of a player, attributes of an action.

10. Different conditions to advance/move to the next level.

11. Any titles or text or fonts in the game scenes, spelling mistakes, legal text etc.

12. Game pause and different options related to it, hints in the game, any easter eggs.

13. Scrolling in the game.

14. Any movie clips in the game etc.

15. Different levels - with increased levels of difficulty.

16. Artificial Intelligence logic (if any).

17. Player movement, positioning.

18. Ease of use.

19. Any special effects.

20. Any other objects in the game - each object separately and how one object interacts with other.

21. Stopping and closing a game at certain level and opening the game at the same place you left it.

22. Test for platform compatibility (if any).

23. Loading time for the game under different scenarios.

24. Test for localization.

25. Networking should be tested thoroughly.

"Black Box" focuses on the functional characteristic of the game e.g. testing the UI – graphics, animations, overall look and feel, and the actual playing part.

"White Box" focuses on the architecture and integration characteristic of the game e.g. the use of a database, tests performed by developers prior to submitting new code for integration with the rest of the game, and so on.

Along with the positive scenarios, negative scenarios in game testing should not be ignored e.g. loading a game with less than required memory etc.

Things to keep in mind while testing games:

- You MUST be familiar with the game rules and then try to test the game against these rules.

- You should always try to check that the game should not crash or freeze in case of minor pauses or the characters should not move out of the bounds at any stage.

A table comparing a Gamer and a Tester: 

	Gamer	Tester
Purpose	Fun	Mastery
Exploration	No	Yes
Genres	Limited	No Prefrences
Focus	Play Speed/accuracy	Skill/achievements
Avoids	Bad Games	Nothing

[Source of above table:Book: Game Development Essentials: Game QA & Testing by Luis Levy & Jeannie Novak]

You can prepare different DOCUMENTS on game testing, if the documentation will be good, the testing will be smooth and better: 

-Requirements document containing features, internal & external design of the game, how to do game testing, Definition of Done etc.

-Game Testing Test Plan (What kind of testing needs to be done, positive, negative etc).

-Test Design document (e.g. definition, guidelines, templates etc of preparing test plan document).

-Test cases depicting each and every scenario etc.

A realtime game tester requirement on a company website:

Your primary responsibilities as a tester will include bug testing and reporting, game balance and game feature testing. Game testing is fun, but it can be demanding. You'll perform traditional feature testing using testing methodologies that you'll learn on the job, and you'll assist the design team in identifying imbalances in game play. You will be an expert on the game and be able to notice any deviation from the correct design and functionality, no matter how small. You'll be expected to work hard, often focusing on very specific, detailed problems. Excellent written and spoken communication skills are crucial to relay what you found to the rest of the team. Patience and tenacity are important traits to demonstrate, as the job requires you to "isolate" every bug and figure out how to replicate it so that it can be fixed.

Some pretty useful resources on game testing:

1. A whitepaper on Systematic Approach to Game Testing

Link

2. Game Testing on Windows, Mac & Linux Quality Assurance Testing in Game Testing Domain– A Case Study

Link

3. Book: Game Testing All in One by Charles P. Schultz, Robert Bryant and Tim Langdell 

4. Testing Strategy for Games

Link

5. Book Extract: Game QA & Testing - Ready, Set, Go!

Game Career Guide here presents an extract from Luis Levy & Jeannie Novak's book Game QA & Testing, a guide to entering the industry through the "traditional" route -- becoming a game tester. This helpful chapter provides information on how to really get in there and get the job.

Link

6. Testing Video Games Can't Possibly Be Harder Than an Afternoon With Xbox, Right?

Link

7. How Video Game Testers Work

Introduction to How Video Game Testers Work, The Need for Video Game Testers, Video Game Tester Responsibilities, Is Video Game Testing a Dream Job?, Becoming a Video Game Tester 

Link

8. MEMOIRS OF A GAME TESTER

A personal story and tips on how to break into the games industry

Link

9. Play games, give opinions, get free software!

Come to Microsoft, play games, give your opinion – and we’ll give you free software.

Link

10. Book: Game Development Essentials: Game QA & Testing by Luis Levy & Jeannie Novak

11. Book: How to Become a Game Tester L. P. Klages

12. Book: Game Usability: Advancing the Player Experience By Katherine Isbister, Noah Schaffer

4 ways to get & count objects in QTP

Imagine simple and practical QTP tasks:

• How to count all links on Web page?
• How to get them and click each link?
• How to get all WebEdits and check their values?

I'm going to show 4 approaches how to get lists of UI controls and process them (for example get their count).
As an example, I will work with links on Google Labs page. My goal is to get the list of links and count them.

I've added Google Labs page to my Object Repository and now it looks like:

I use Object Repository (OR) to simplify my demo-scripts.
Since the browser & the page were added to OR, we can use them later like:
Browser("Google Labs").Page("Google Labs").

Now we are ready to start!

1. QTP Descriptive Programming (QTP DP) and ChildObjects QTP function
   The approach uses Description object, which contains a 'mask' for objects we would like to get.
   QTP script is:
   
   Set oDesc = Description.Create()
   oDesc("micclass").Value = "Link"
   Set Links = Browser("Google Labs").Page("Google Labs").ChildObjects(oDesc)
   Msgbox "Total links: " & Links.Count
   The result of this QTP script is:

ChildObjects returns the collection of child objects matched the description ("micclass" is "Link") and  contained within the object (Page("Google Labs")).

2. Object QTP property and objects collections
    QTP can work with DOM:

Set Links = Browser("Google Labs").Page("Google Labs").Object.Links
Msgbox "Total links: " & Links.Length

I use Object property of Page object. It represents the HTML document in a given browser window.
This document contains different collections - forms, frames, images, links, etc.
And we use Length property to get the number of items in a collection.

The result is the same as for the previous QTP script:

3. Object QTP property and GetElementsByTagName method
Again, we can get access to the HTML document and use its GetElementsByTagName method. 
As the name says, GetElementsByTagName method returns a collection of objects with the specified tag.
Since we are going to get all link, we should use "a" tag.

QTP script is:

Set Links = Browser("Google Labs").Page("Google Labs").Object.GetElementsByTagName("a")
Msgbox "Total links: " & Links.Length

The result is the following:

Note: There is another way how to select objects by tag name:

Set Links = Browser("Google Labs").Page("Google Labs").Object.all.tags("a")
Msgbox "Total links: " & Links.Length

The result will be the same. 69 link will be found.

4. XPath queries in QTP

1. The idea of this approach is to use XPath queries on a source code of Web page.
   For example, "//a" XPath query returns all "a" nodes (= links) from XML file.
   
   There is one problem. Web page contains HTML code, which looks like XML code but actually it is not.
   For example:
   • HTML code can contain unclosed img or br tags, XML code cannot.
   • HTML code is a case-insensitive markup language, XML is a case-sensitive markup language, etc
     More details here.
   
   So, we have to convert HTML source code into XML. The converted code is named as XHTML.
   
   You can convert HTML documents into XHTML using an Open Source HTML Tidy utility.
   You can find more info about how to convert HTML code into XHTML code here.
   
   I will use the final QTP script from this page, a bit modified:
   
   ' to get an HTML source code of Web page
   HtmlCode = Browser("Google Labs").Page("Google Labs").Object.documentElement.outerHtml
   
   ' save HTML code to a local file
   Set fso = CreateObject("Scripting.FileSystemObject")
   Set f = fso.CreateTextFile("C:\HtmlCode.html", True, -1)
   f.Write(HtmlCode)
   f.Close()
   
   ' run tidy.exe to convert HTML to XHTML 
   Set oShell = CreateObject("Wscript.shell")
   oShell.Run "C:\tidy.exe --doctype omit -asxhtml -m -n C:\HtmlCode.html", 1, True ' waits for tidy.exe to be finished
   
   ' create MSXML parser
   Set objXML = CreateObject("MSXML2.DOMDocument.3.0")
   objXML.Async = False 
   objXML.Load("C:\HtmlCode.html")
   
   XPath = "//a" ' XPath query means to find all links
   Set Links = objXML.SelectNodes(XPath)
   Msgbox "Total links: " & Links.Length
   
   Note: you can download tidy.exe here for above QTP script.
   
   This QTP script leads to the same results - 69 links found:

(Click the image to enlarge it)

5. Bonus approah 

      Why don't you count all Wen page objects manually? :) Open a source code of the page and start  counting :)
Just joking :)

Summary:

• I shown 4 practical approaches how to count Web page links.Similarly you can process images, webedits, etc
• Each approach gets a list of objects.
• First approach (QTP DP + ChildObjects) is the most easy
• Second & third approaches (Object + collections; Object + GetElementsByTagName) will work on Internet Explorer, because they use DOM methods
• Fours approach is biggest but it is more powerful. It allows to use complex XPath queries.

QTP - How to get all Object Indentification Properties?

There are two ways how to get all properties of an object in QuickTest Professional:

1. Manually
2. Programmatically

Use QTP Object Spy to get manually object properties.
I've captured properties of ''Advanced Search" link from Google's page:

So, QTP Object Spy shows these values:

Using QTP Object Spy you can get Run-time Object Properties and Test Object Properties.

It's possible to get these properties programatically:

• The GetTOProperty and GetTOProperties methods enable you to retrieve a specific property value or all the properties and values that QuickTest uses to identify an object.
• The GetROProperty returns the current value of the test object property from the object in the application.

GetTOProperty differs from the GetROProperty method:

• GetTOProperty returns the value from the test object's description.
  Test Object Properties are stored in the QTP Object Repository.
• GetROProperty returns the current property value of the object in the application during the test run.
  QTP reads Run-time Object Properties from actual objects during the runnins can be read and accessed during the run session.

That means that when you work with objects using QTP Descriptive Programming (DP), you will be able to access run-time object properties only (using GetROProperty function). Test object properties (using GetTOProperty function) will not be accessed, because QTP DP doesn't work Object Repository.

There is a problem with Run-time object properties.
In contrast to GetTOProperties (which returns the collection of all properties and values used to identify the test object), GetROPropertiesfunction does NOT exist!
Once again - GetROProperties function does NOT exist!


Well, how to get all Object Indentification Properties of an object? 
Answer: We can read them from Windows Registry.

The following registry key contains properties of a given test object:

HKEY_LOCAL_MACHINE\SOFTWARE\Mercury Interactive\QuickTest Professional\MicTest\Test Objects\_Test_Object_\Properties

For example, I've opened:
HKEY_LOCAL_MACHINE\SOFTWARE\Mercury Interactive\QuickTest Professional\MicTest\Test Objects\Link\Properties 

and I've got properties of Link object:

Please note that you can find the same Link Identification Properties in QuickTest Professional Help:

QTP Object Identification Properties can be used:

• in the object repository description
• in programmatic descriptions
• in checkpoint and output value steps
• and as argument values for the GetTOProperty and GetROProperty methods

So we have to read all Identification Properties from the registry.
This QTP code reads Link Identification Properties:

Const HKEY_LOCAL_MACHINE = &H80000002
Set oReg = GetObject("winmgmts:{impersonationLevel=impersonate}!\\.\root\default:StdRegProv")

sKeyPath = "SOFTWARE\Mercury Interactive\QuickTest Professional\MicTest\Test Objects\Link\Properties"
oReg.EnumValues HKEY_LOCAL_MACHINE, sKeyPath, arrNames

As a result, arrNames array contains all names of properties.
To prove my words I use this QTP script:

sNames = "Identfication Properties:" & vbNewLine

For i = 0 to UBound(arrNames)    sNames = sNames & arrNames(i) & vbNewLine
Next

MsgBox sNames

The result is:

Compare these Link Identification Properties with properties from the registry. They are the same!

So, we can read names of properties.

Next step is to read their values. It can be archived using GetTOProperty or GetROProperty.
Also, I'm going to show how GetTOProperty and GetROProperty work for Test Object (located in QTP Object Repository) and Run-time Object (actual object, created during the run session).

1. Properties of Test Object
   QTP script is:
   
   ' Link("Advanced Search") is an object from QTP Object Repository
   Set TestLink = Browser("Google").Page("Google").Link("Advanced Search")
   
   sNamesTO = "GetTOProperty for Test Object" & vbNewLine & "Identfication Properties: Values" & vbNewLine
   sNamesRO = "GetROProperty for Test Object" & vbNewLine & "Identfication Properties: Values" & vbNewLine
   
   For i = 0 to UBound(arrNames)
       sNamesTO = sNamesTO & arrNames(i) & ": " & TestLink.GetTOProperty(arrNames(i)) & vbNewLine
       sNamesRO = sNamesRO & arrNames(i) & ": " & TestLink.GetROProperty(arrNames(i)) & vbNewLine
   Next
   
   MsgBox sNamesTO
   MsgBox sNamesRO
• Test Object Properties of Test Object
  Test Object Properties of Test Object and their values are:
  
  
  
  
• Run-time Object Properties of Test ObjectRun-time Object Properties of Test Object and their values are:

        2. Properties of Run-time Object             QTP script is:

' Link("text:=Advanced Search") is a dynamic run-time object
Set TestLink = Browser("Google").Page("Google").Link("text:=Advanced Search")

sNamesTO = "GetTOProperty for Run-time Object" & vbNewLine & "Identfication Properties: Values" &vbNewLine
sNamesRO = "GetROProperty for Run-time Object" & vbNewLine & "Identfication Properties: Values" &vbNewLine

For i = 0 to UBound(arrNames)
    sNamesTO = sNamesTO & arrNames(i) & ": " & TestLink.GetTOProperty(arrNames(i)) & vbNewLine
    sNamesRO = sNamesRO & arrNames(i) & ": " & TestLink.GetROProperty(arrNames(i)) & vbNewLine
Next

MsgBox sNamesTO
MsgBox sNamesRO

• Test Object Properties of Run-time ObjectTest Object Properties of Run-time Object and their values are:

• Why almost all properties are empty?
  
  As I said, GetTOProperty function gets values from Test Object, which is stored in QTP Object Repository. Since Run-time Object is a dynamic object, it's not stored in QTP Object Repository. That's why GetTOProperty function cannot read object's properties.
  
  Look at the above screenshot again. The only one property ('text') contains its value ('Advanced Search'). We used this property to create description for our link:
  
  Set TestLink = Browser("Google").Page("Google").Link("text:=Advanced Search")
  That's why this Run-time Object contains the only property.
  
• Run-time Object Properties of Run-time ObjectRun-time Object Properties of Run-time Object and their values are:

As you can see, we got the same Run-time Object Properties both for Test Object and for Run-time Object. I can explain it.
During the run session, QTP creates a Run-time copy of Test Object. That's why Run-time Object Properties were the same for Test Object and Run-time Object.

Note: You can download final QTP script here.

Interview questions on WinRunner

1. How you used WinRunner in your project? - Yes, I have been using WinRunner for creating automated scripts for GUI, functional and regression testing of the AUT.
2. Explain WinRunner testing process? - WinRunner testing process involves six main stages
   • Create GUI Map File so that WinRunner can recognize the GUI objects in the application being tested
   • Create test scripts by recording, programming, or a combination of both. While recording tests, insert checkpoints where you want to check the response of the application being tested.
   • Debug Test: run tests in Debug mode to make sure they run smoothly
   • Run Tests: run tests in Verify mode to test your application.
   • View Results: determines the success or failure of the tests.
   • Report Defects: If a test run fails due to a defect in the application being tested, you can report information about the defect directly from the Test Results window.
3. What is contained in the GUI map?  - WinRunner stores information it learns about a window or object in a GUI Map. When WinRunner runs a test, it uses the GUI map to locate objects. It reads an object.s description in the GUI map and then looks for an object with the same properties in the application being tested. Each of these objects in the GUI Map file will be having a logical name and a physical description. There are 2 types of GUI Map files. Global GUI Map file: a single GUI Map file for the entire application. GUI Map File per Test: WinRunner automatically creates a GUI Map file for each test created.
4. How does WinRunner recognize objects on the application? - WinRunner uses the GUI Map file to recognize objects on the application. When WinRunner runs a test, it uses the GUI map to locate objects. It reads an object.s description in the GUI map and then looks for an object with the same properties in the application being tested.
5. Have you created test scripts and what is contained in the test scripts?  - Yes I have created test scripts. It contains the statement in Mercury Interactive.s Test Script Language (TSL). These statements appear as a test script in a test window. You can then enhance your recorded test script, either by typing in additional TSL functions and programming elements or by using WinRunner.s visual programming tool, the Function Generator.
6. How does WinRunner evaluate test results? - Following each test run, WinRunner displays the results in a report. The report details all the major events that occurred during the run, such as checkpoints, error messages, system messages, or user messages. If mismatches are detected at checkpoints during the test run, you can view the expected results and the actual results from the Test Results window.
7. Have you performed debugging of the scripts? - Yes, I have performed debugging of scripts. We can debug the script by executing the script in the debug mode. We can also debug script using the Step, Step Into, Step out functionalities provided by the WinRunner.
8. How do you run your test scripts? - We run tests in Verify mode to test your application. Each time WinRunner encounters a checkpoint in the test script, it compares the current data of the application being tested to the expected data captured earlier. If any mismatches are found, WinRunner captures them as actual results.
9. How do you analyze results and report the defects? - Following each test run, WinRunner displays the results in a report. The report details all the major events that occurred during the run, such as checkpoints, error messages, system messages, or user messages. If mismatches are detected at checkpoints during the test run, you can view the expected results and the actual results from the Test Results window. If a test run fails due to a defect in the application being tested, you can report information about the defect directly from the Test Results window. This information is sent via e-mail to the quality assurance manager, who tracks the defect until it is fixed.
10. What is the use of Test Director software? - TestDirector is Mercury Interactive.s software test management tool. It helps quality assurance personnel plan and organize the testing process. With TestDirector you can create a database of manual and automated tests, build test cycles, run tests, and report and track defects. You can also create reports and graphs to help review the progress of planning tests, running tests, and tracking defects before a software release.
11. Have you integrated your automated scripts from TestDirector? - When you work with WinRunner, you can choose to save your tests directly to your TestDirector database or while creating a test case in the TestDirector we can specify whether the script in automated or manual. And if it is automated script then TestDirector will build a skeleton for the script that can be later modified into one which could be used to test the AUT.
12. What are the different modes of recording? - There are two type of recording in WinRunner.  Context Sensitive recording records the operations you perform on your application by identifying Graphical User Interface (GUI) objects. Analog recording records keyboard input, mouse clicks, and the precise x- and y-coordinates traveled by the mouse pointer across the screen.
13. What is the purpose of loading WinRunner Add-Ins?  - Add-Ins are used in WinRunner to load functions specific to the particular add-in to the memory. While creating a script only those functions in the add-in selected will be listed in the function generator and while executing the script only those functions in the loaded add-in will be executed else WinRunner will give an error message saying it does not recognize the function.
14. What are the reasons that WinRunner  - WinRunner fails to identify an object in a GUI due to various reasons.  The object is not a standard windows object. If the browser used is not compatible with the WinRunner version, GUI Map Editor will not be able to learn any of the objects displayed in the browser window.
15. What is meant by the logical name of the object? - An object.s logical name is determined by its class. In most cases, the logical name is the label that appears on an object.
16. If the object does not have a name then what will be the logical name?  - If the object does not have a name then the logical name could be the attached text.
17. What is the different between GUI map and GUI map files? - The GUI map is actually the sum of one or more GUI map files. There are two modes for organizing GUI map files. Global GUI Map file: a single GUI Map file for the entire application. GUI Map File per Test: WinRunner automatically creates a GUI Map file for each test created.
GUI Map file is a file which contains the windows and the objects learned by the WinRunner with its logical name and their physical description.
18. How do you view the contents of the GUI map? - GUI Map editor displays the content of a GUI Map. We can invoke GUI Map Editor from the Tools Menu in WinRunner. The GUI Map Editor displays the various GUI Map files created and the windows and objects learned in to them with their logical name and physical description.
19. When you create GUI map do you record all the objects of specific objects?  - If we are learning a window then WinRunner automatically learns all the objects in the window else we will we identifying those object, which are to be learned in a window, since we will be working with only those objects while creating scripts.

LoadRunner interview questions

1. What is load testing? - Load testing is to test that if the application works fine with the loads that result from large number of simultaneous users, transactions and to determine weather it can handle peak usage periods.
2. What is Performance testing? - Timing for both read and update transactions should be gathered to determine whether system functions are being performed in an acceptable timeframe. This should be done standalone and then in a multi user environment to determine the effect of multiple transactions on the timing of a single transaction.
3. Did u use LoadRunner? What version? - Yes. Version 7.2.
4. Explain the Load testing process? -
   Step 1: Planning the test. Here, we develop a clearly defined test plan to ensure the test scenarios we develop will accomplish load-testing objectives. Step 2: Creating Vusers. Here, we create Vuser scripts that contain tasks performed by each Vuser, tasks performed by Vusers as a whole, and tasks measured as transactions. Step 3: Creating the scenario. A scenario describes the events that occur during a testing session. It includes a list of machines, scripts, and Vusers that run during the scenario. We create scenarios using LoadRunner Controller. We can create manual scenarios as well as goal-oriented scenarios. In manual scenarios, we define the number of Vusers, the load generator machines, and percentage of Vusers to be assigned to each script. For web tests, we may create a goal-oriented scenario where we define the goal that our test has to achieve. LoadRunner automatically builds a scenario for us. Step 4: Running the scenario.We emulate load on the server by instructing multiple Vusers to perform tasks simultaneously. Before the testing, we set the scenario configuration and scheduling. We can run the entire scenario, Vuser groups, or individual Vusers. Step 5: Monitoring the scenario.We monitor scenario execution using the LoadRunner online runtime, transaction, system resource, Web resource, Web server resource, Web application server resource, database server resource, network delay, streaming media resource, firewall server resource, ERP server resource, and Java performance monitors. Step 6: Analyzing test results. During scenario execution, LoadRunner records the performance of the application under different loads. We use LoadRunner.s graphs and reports to analyze the application.s performance.
5. When do you do load and performance Testing? - We perform load testing once we are done with interface (GUI) testing. Modern system architectures are large and complex. Whereas single user testing primarily on functionality and user interface of a system component, application testing focuses on performance and reliability of an entire system. For example, a typical application-testing scenario might depict 1000 users logging in simultaneously to a system. This gives rise to issues such as what is the response time of the system, does it crash, will it go with different software applications and platforms, can it hold so many hundreds and thousands of users, etc. This is when we set do load and performance testing.
6. What are the components of LoadRunner? - The components of LoadRunner are The Virtual User Generator, Controller, and the Agent process, LoadRunner Analysis and Monitoring, LoadRunner Books Online.
7. What Component of LoadRunner would you use to record a Script? - The Virtual User Generator (VuGen) component is used to record a script. It enables you to develop Vuser scripts for a variety of application types and communication protocols.
8. What Component of LoadRunner would you use to play Back the script in multi user mode? - The Controller component is used to playback the script in multi-user mode. This is done during a scenario run where a vuser script is executed by a number of vusers in a group.
9. What is a rendezvous point? - You insert rendezvous points into Vuser scripts to emulate heavy user load on the server. Rendezvous points instruct Vusers to wait during test execution for multiple Vusers to arrive at a certain point, in order that they may simultaneously perform a task. For example, to emulate peak load on the bank server, you can insert a rendezvous point instructing 100 Vusers to deposit cash into their accounts at the same time.
10. What is a scenario? - A scenario defines the events that occur during each testing session. For example, a scenario defines and controls the number of users to emulate, the actions to be performed, and the machines on which the virtual users run their emulations.
11. Explain the recording mode for web Vuser script? - We use VuGen to develop a Vuser script by recording a user performing typical business processes on a client application. VuGen creates the script by recording the activity between the client and the server. For example, in web based applications, VuGen monitors the client end of the database and traces all the requests sent to, and received from, the database server. We use VuGen to: Monitor the communication between the application and the server; Generate the required function calls; and Insert the generated function calls into a Vuser script.
12. Why do you create parameters? - Parameters are like script variables. They are used to vary input to the server and to emulate real users. Different sets of data are sent to the server each time the script is run. Better simulate the usage model for more accurate testing from the Controller; one script can emulate many different users on the system.
13. What is correlation? Explain the difference between automatic correlation and manual correlation? - 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). Automatic correlation is where we set some rules for correlation. It can be application server specific. Here values are replaced by data which are created by these rules. In manual correlation, the value we want to correlate is scanned and create correlation is used to correlate.
14. How do you find out where correlation is required? Give few examples from your projects? - Two ways: First 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. Secondly, we can record two scripts and compare them. We can look up the difference file to see for the values which needed to be correlated.  In my project, there was a unique id developed for each customer, it was nothing but Insurance Number, it was generated automatically and it was sequential and this value was unique. I had to correlate this value, in order to avoid errors while running my script. I did using scan for correlation.
15. Where do you set automatic correlation options? - Automatic correlation from web point of view can be set 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.
16. What is a function to capture dynamic values in the web Vuser script? - Web_reg_save_param function saves dynamic data information to a parameter.
17. When do you disable log in Virtual User Generator, When do you choose standard and extended logs? - 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. Standard Log Option: When you select
    Standard log, it creates a standard log of functions and messages sent during script execution to use for debugging. Disable this option for large load testing scenarios. When you copy a script to a scenario, logging is automatically disabled Extended Log Option: Select
    extended log to create an extended log, including warnings and other messages. Disable this option for large load testing scenarios. When you copy a script to a scenario, logging is automatically disabled. We can specify which additional information should be added to the extended log using the Extended log options.
18. How do you debug a LoadRunner script? - 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 your 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.
19. How do you write user defined functions in LR? Give me few functions you wrote in your previous project? - 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* <function name>(char*, char*)Examples of user defined functions are as follows:GetVersion, GetCurrentTime, GetPltform are some of the user defined functions used in my earlier project.
20. What are the changes you can make in run-time settings? - The Run Time Settings that we make are: a) Pacing - It has iteration count. b) Log - Under this we have Disable Logging Standard Log and c) Extended Think Time - In think time we have 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 whether each step as a transaction.
21. Where do you set Iteration for Vuser testing? - We set Iterations in the Run Time Settings of the VuGen. The navigation for this is Run time settings, Pacing tab, set number of iterations.
22. How do you perform functional testing under load? - Functionality under load can be tested by running several Vusers concurrently. By increasing the amount of Vusers, we can determine how much load the server can sustain.
23. What is Ramp up? How do you set this? - This option is used to gradually increase the amount of Vusers/load on the server. An initial value is set and a value to wait between intervals can be
    specified. To set Ramp Up, go to ‘Scenario Scheduling Options’
24. What is the advantage of running the Vuser as thread? - VuGen provides the facility to use multithreading. This enables more Vusers to be run per
    generator. If the Vuser is run as a process, the same driver program is loaded into memory for each Vuser, thus taking up a large amount of memory. This limits the number of Vusers that can be run on a single
    generator. If the Vuser is run as a thread, only one instance of the driver program is loaded into memory for the given number of
    Vusers (say 100). Each thread shares the memory of the parent driver program, thus enabling more Vusers to be run per generator.
25. If you want to stop the execution of your script on error, how do you do that? - The lr_abort function aborts the execution of a Vuser script. It instructs the Vuser to stop executing the Actions section, execute the vuser_end section and end the execution. This function is useful when you need to manually abort a script execution as a result of a specific error condition. When you end a script using this function, the Vuser is assigned the status "Stopped". For this to take effect, we have to first uncheck the .Continue on error. option in Run-Time Settings.  
26. What is the relation between Response Time and Throughput? - The Throughput graph shows the amount of data in bytes that the Vusers received from the server in a second. When we compare this with the transaction response time, we will notice that as throughput decreased, the response time also decreased. Similarly, the peak throughput and highest response time would occur approximately at the same time.
27. Explain the Configuration of your systems? - The configuration of our systems refers to that of the client machines on which we run the Vusers. The configuration of any client machine includes its hardware settings, memory, operating system, software applications, development tools, etc. This system component configuration should match with the overall system configuration that would include the network infrastructure, the web server, the database server, and any other components that go with this larger system so as to achieve the load testing objectives.
28. How do you identify the performance bottlenecks? - Performance Bottlenecks can be detected by using monitors. These monitors might be application server monitors, web server monitors, database server monitors and network monitors. They help in finding out the troubled area in our scenario which causes increased response time. The measurements made are usually performance response time, throughput, hits/sec, network delay graphs, etc.
29. If web server, database and Network are all fine where could be the problem? - The problem could be in the system itself or in the application server or in the code written for the application.
30. How did you find web server related issues? - Using Web resource monitors we can find the performance of web servers. Using these monitors we can analyze throughput on the web server, number of hits per second that
    occurred during scenario, the number of http responses per second, the number of downloaded pages per second.
31. How did you find database related issues? - By running .Database. monitor and help of .Data Resource Graph. we can find database related issues. E.g. You can specify the resource you want to measure on before running the controller and than you can see database related issues
32. Explain all the web recording options?
33. What is the difference between Overlay graph and Correlate graph? - Overlay Graph: It overlay the content of two graphs that shares a common x-axis. Left Y-axis on the merged graph show.s the current graph.s value & Right Y-axis show the value of Y-axis of the graph that was merged. Correlate Graph:Plot the Y-axis of two graphs against each other. The active graph.s Y-axis becomes X-axis of merged graph. Y-axis of the graph that was merged becomes merged graph.s Y-axis.
34. How did you plan the Load? What are the Criteria? - Load test is planned to decide the number of users, what kind of machines we are going to use and from where they are run. It is based on 2 important documents, Task Distribution Diagram and Transaction profile. Task Distribution Diagram gives us the information on number of users for a particular transaction and the time of the load. The peak usage and off-usage are decided from this Diagram. Transaction profile gives us the information about the transactions name and their priority levels with regard to the scenario we are deciding.
35. What does vuser_init action contain? - Vuser_init action contains procedures to login to a server.
36. What does vuser_end action contain? - Vuser_end section contains log off procedures.  
37. What is think time? How do you change the threshold? -   Think time is the time that a real user waits between actions. Example: When a user receives data from a server, the user may wait several seconds to review the data before responding. This delay is known as the think time. Changing the Threshold: Threshold level is the level below which the recorded think time will be ignored. The default value is five (5) seconds. We can change the think time threshold in the Recording options of the Vugen.
38. What is the difference between standard log and extended log? - The standard log sends a subset of functions and messages sent during script execution to a log. The subset depends on the Vuser type Extended log sends a detailed script execution messages to the output log. This is mainly used during debugging when we want information about: Parameter substitution. Data returned by the server. Advanced trace.
39. Explain the following functions: - lr_debug_message - The lr_debug_message function sends a debug message to the output log when the specified message class is set. lr_output_message - The lr_output_message function sends notifications to the Controller Output window and the Vuser log file.lr_error_message - The lr_error_message function sends an error message to the LoadRunner Output window. lrd_stmt - The lrd_stmt function associates a character string (usually a SQL statement) with a cursor. This function sets a SQL statement to be processed. lrd_fetch - The lrd_fetch function fetches the next row from the result set.
40. Throughput -  If the throughput scales upward as time progresses and the number of Vusers increase, this indicates that the bandwidth is sufficient. If the graph were to remain relatively flat as the number of Vusers increased, it would
    be reasonable to conclude that the bandwidth is constraining the volume of
    data delivered. 
41. Types of Goals in Goal-Oriented Scenario -  Load Runner provides you with five different types of goals in a goal oriented scenario:
    • The number of concurrent Vusers
    • The number of hits per second
    • The number of transactions per second
    • The number of pages per minute
    • The transaction response time that you want your scenario
42. Analysis Scenario (Bottlenecks): In Running Vuser graph correlated with the response time graph you can see that as the number of Vusers increases, the average response time of the check itinerary transaction very gradually increases. In other words, the average response time steadily increases as the load
    increases. At 56 Vusers, there is a sudden, sharp increase in the average response
    time. We say that the test broke the server. That is the mean time before failure (MTBF). The response time clearly began to degrade when there were more than 56 Vusers running simultaneously.
43. What is correlation? Explain the difference between automatic correlation and manual correlation? - 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). Automatic correlation is where we set some rules for correlation. It can be application server specific. Here values are replaced by data which are created by these rules. In manual correlation, the value we want to correlate is scanned and create correlation is used to correlate.
44. Where do you set automatic correlation options? - Automatic correlation from web point of view, can be set 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.
45. What is a function to capture dynamic values in the web vuser script? - Web_reg_save_param function saves dynamic data information to a parameter.