Loadrunner Interview Questions

1) What is load testing?

Answer: Load testing is a kind of performance testing which determines a system’s performance under real-life load conditions. It can give an idea how an application behaves when multiple user simultaneously access the application.

2) What is Performance testing?

Answer: Performance testing involves testing software applications to ensure that the application performs under their expected workload. Main goal of performance testing is to eliminate performance bottlenecks and not to find bugs.

3) What are the components of LoadRunner?

 

  • Vugen(Virtual User Generator):Vugen helps in creating scripts for single user, do the required enhancements to the script in a such a way that it can be run for multiple user.
  • Controller: The purpose of Controller is to Run the load test and monitor the servers during load test execution
  • Analysis: Anlyzer can be used to analyze the results and create graphs and reports.

 

4) What is a rendezvous point?

Rendezvous is used for achieving concurrency during load testing. Rendezvous point 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.

5)What is Ramp up? How do you set this?

Ramp up 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’

6)Types of Goals in 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

 

7) What kind of problem we can face regarding hardware, software,  network and memory bottleneck during the performance test?

The possible issues amongst others could be –

 

  • Lack of Hardware
  • Memory Leakage
  • Network related issues.
  • Applicaton/Software error

 

8)What is the difference between hits/second and requests/second?

Hits per second means the number of hits the vserver receives in one sec from the vuser and the request per second is the no. of request the vuser will request from the server

9)What is the vuser in the scenario?

The vuser is virtual users nothing but those who simulate the real users.The virtual users who take the place of real users operating client software, such as IE sending requests using the HTTP protocol to IIS or Apache web servers

10)What are the advantages of using load runner?

 

  • Uses ANSI C as the default programming language1 and other languages like Java and VB.
  • Excellent monitoring and analysis interface where you can see reports in easy to understand colored charts and graphics.
  • GUI generated script through a one click recording, of course you would need to modify the script according to your needs.
  • Excellent tutorials, exhaustive documentation and active tool support from HP.

 

11)What are monitors?

Monitors are used to “monitor” performance bottlenecks. They are used in Controller section of Load Runner

12)What is the benefit of running a Vuser script as a thread?

 

  • VuGen provides the facility to use multithreading.
  • 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

 

13)How many types of graphs are available in LoadRunner and what are they?

 

  • Hits per second graph
  • Pages download per second graph
  • Transaction response time (under load) graph
  • Transaction response time (percentile) graph and
  • Network delay time graph

 

14)Which protocols are supported by Loadrunner ?

 

  • Distributed Components: For COM/DCOM, Corba-Java, and Rmi -Java protocols.
  • E-business: For FTP, LDAP, Palm, Web (HTTP/HTML), Web Services, and the dual Web/Winsocket protocols.
  • Enterprise Java Beans: For EJB Testing and Rmi-Java protocols.

 

15)How many VUsers are required for load testing ?

The number of VUsers required depends on your system under test , network configurations , hardware settings, memory, operating system, software applications objective of performance test.

16)What is the difference between load , performance  testing ?

Performance testing is the testing, which is performed, to ascertain how the components of a system are performing, given a particular situation.

Load testing is meant to test the system by constantly and steadily increasing the load on the system till the time it reaches the threshold limit.

17)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

18) 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.

19) What are the three sections of a Vuser script and what is the purpose of each one?

vuser_init- a login to a serve

Actions- Used when recording client activity

vuser action-used when recording a log off procedure

 

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Explaining Load Runner Specific Features

Loadrunner is a trusted name in the field of software testing. There certain features of Loadrunner which makes it stand apart from other tools present in the market. Some of the Loadrunner specific features are as follows :

  • Think Time: Think time is the amount of time for which the script will not perform any action. While recording the browsing action, if a user doesn’t perform any action for a specific period of time, it is taken into account as think time. While modifying the recorded script think time can be inserted manually.
  • Rendezvous: Sometimes we need to emulate heavy user load on your system. To achieve this, we synchronize Vusers to perform a task at exactly the same moment. You configure multiple Vusers to act simultaneously by creating a rendezvous point. When a Vuser arrives at the rendezvous point, it waits until all Vusers arrive.When all Vusers arrive, the Vusers are released.
  • Parameters: To make some of the dynamic data supplied by the users such as login details, search term should be replaced with parameters and so that the script is not hard-coded and these parameter values are different for some vusers, thus making the load testing more realistic.
  • Correlation: Dynamic variables like cookies, session id etc changes every time we connect with the website.While recording the script these variables values are hard coded. So when we run the script it shows error and the script is not passed as these values should be different every time we connect to that particular site.Correlation helps us overcome this problem.
  • Transaction: Transaction are those those functions in your script that should be monitored with details.Some functions like login, cart etc are important for the website,thus their response time is very important. In that scenario insert transactions to get a detailed summary about those actions

 

Hp Loadrunner Installation

Installation of LoadRunner

Well if you are reading this post, then you must be having a fair idea about what the LoadRunner software is and what it is used for. Now you must be having an urge to try out this software for testing your personal application, software, and website or may be for educational purpose. But before you try out this awesome software you have to get the installation files and also install it on your machine in a correct manner so that you don’t have to Google every now and then to solve out various problems. Well this post is there to help you out with the installation of LoadRunner on your machine.

Since LoadRunner is the most famous testing software currently used in the industry and is made by HP, it is obvious that it doesn’t come cheap. This software cost around $915,200 for 3 years (approx), which is whole lot of money for any individual or even for a testing company. But we can download a 10 day LoadRunner trial version to try out our hands on this software. One can download the trial version from here(http://www8.hp.com/us/en/software-solutions/software.html?compURI=1175451#.UCQSyZ3iaSE). After selecting the option to download, you will be required to fill a form and an email will be sent to your email account containing a link to download the software. The size of the software is around 3.78 GB. After you download the software, you are all ready to install the software but before that you have to make sure that your machine meets the required specifications as mentioned below:

The following prerequisite software needs to be installed:

  • .NET Framework 3.5 SP1
  • Microsoft Data Access Components (MDAC) 2.8 SP1 (or later)
  • Microsoft Windows Installer 3.1
  • Microsoft Core XML Services (MSXML) 6.0
  • Microsoft Visual C++ 2005 SP1 Redistributable Package (x86)
  • Microsoft Visual C++ 2008 Redistributable Package (x86)
  • Web Services Enhancements (WSE) 2.0 SP3 for Microsoft .NET Redistributable Runtime MSI
  • Web Services Enhancements (WSE) 3.0 for Microsoft .NET Redistributable Runtime MSI
  • Strawberry Perl 5.10.

Even if any of the above thing is missing, you don’t have to panic, because the LoadRunner installation wizard will download and install it for you if they are found missing. Now that is a cool feature.

Beyond those requirements there are certain other requirements that also have to be followed for the smooth running of LoadRunner.

The system requirements for VUGEN, CONTROLLER and ANALYSIS can be summed up as follows:

  • The processor can be Intel Core, Pentium, Xeon, AMD or compatible with a minimum speed of 1 GHz and its recommended to have 2 GHz or above.
  • Operating system ranges from Windows XP to Windows 7 with all versions between them, but to run VUGEN for recording purpose it has to be a 32-bit operating system.
  • Memory should be minimum of 2GB and it is recommended to be 4GB or higher.
  • The screen resolution should be around 1024 X 768.
  • LoadRunner only supports Internet Explorer for the recording purposes.
  • A minimum hard disk space of 2GB is required for it.

Similar type of requirements is also necessary for the Load Generator component of the LoadRunner but if you are using the Pentium processor, hyper threading function should be disabled (Details).

If your machine fulfils this requirement then you can further proceed for the installation part. Now unzip the downloaded file to any location of your choice and then search for the setup file. Clicking on it will load the installation wizard and you can follow the on-screen instructions to successfully install the LoadRunner on your machine. After installation start your program and get set to work.

 

List Of LoadRunner Books:

LoadRunner Books for reference:

1) Performance & Load Testing

2) An Introduction to LoadRunner – A Powerful Performance Testing Tool by HP

3) Let us Learn & Master LoadRunner 9.0

4) Load Test Planning – Especially with LoadRunner

5) Understanding of Load Testing Tools – Especially HP LoadRunner

6) Introduction to HP LoadRunner

7) Building Scripts for LoadRunner

8) Configuration of Run Time Settings for HP LoadRunner

9) Playing Back Scripts in HP LoadRunner

10) Parameterization – Advanced VUser Scripts in HP LoadRunner

11) Enhancing Vuser Scripts in HP LoadRunner

12) Understanding Correlation in HP LoadRunner

13) How to design a Scenario in HP LoadRunner

14) How to Run a Scenario in HP LoadRunner

15) How to do Analysis in HP LoadRunner

16) Understanding Performance testing – The Performance Testing Tool

17) Understanding Analysis Reports in HP LoadRunner

 

 

HP Loadrunner Introduction

HP Loadrunner is a famous tool for performance testing.It stresses your application to desired limits and identifies potential and problematic bottlenecks in client,network or server.

Loadrunner addresses the above issues in following ways :-

  • It has Vusers which act as virtual users and emulate the actions performed by different real users.As multiple vusers run on the same machine it evens helps in curbing the cost of hardware required.
  • Loadrunner Controller helps in controlling all of the vusers from a single point, thus helping the engineer in controlling the activities in an efficient way.
  • LoadRunner monitors the application performance online, enabling you to fine- tune your system during test execution.
  • It automatically records the performance result of the application. It has wide varieties of results to choose from,as required by the engineer.
  • LoadRunner monitors the network and server resources to help you improve performance.
  • As all of the tests are automated these can be saved and run again and again as and when required.