LoadRunner Interview Questions

1.      What is LoadRunner and what is it used for?

Answer: LoadRunner is a performance testing tool used to simulate a heavy load on a system or application to test its strength and identify bottlenecks. It is used to ensure that the system can handle expected user traffic and can identify potential performance issues before the system goes live.

2.      What are the components of LoadRunner?

Answer: The components of LoadRunner include the Virtual User Generator (VuGen), Controller, and Analysis. VuGen is used to record and create scripts, the Controller is used to manage the execution of the load test, and Analysis is used to analyze the results of the test.

3.      What are the different types of load tests that can be performed using LoadRunner?

Answer: LoadRunner can perform several types of load tests, including stress testing, load testing, and capacity testing. Stress testing is used to identify the breaking point of a system, load testing is used to test the system under expected loads, and capacity testing is used to determine the maximum load a system can handle.

4.      How does LoadRunner simulate user load?

Answer: LoadRunner simulates user load by creating virtual users or Vusers. These Vusers can be configured to perform specific actions, such as logging in, searching, or making a purchase, and can be set to run simultaneously to simulate a large number of users accessing the system at the same time.

5.      What are the benefits of using LoadRunner?

Answer: LoadRunner can provide several benefits, including identifying performance bottlenecks, identifying scalability issues, determining system capacity, and validating the performance of the system before it goes live. Additionally, it can be used to optimize the system for better performance and to ensure that the system can handle expected user traffic.

6.      How do you analyze the results of a LoadRunner test?

Answer: LoadRunner provides a tool called Analysis to analyze the results of a test. It allows you to view detailed information about the test, including response times, transaction performance, and error rates. You can also create graphs and reports to help you identify bottlenecks and performance issues.

7.      How to handle dynamic values in LoadRunner?

Answer: In LoadRunner, dynamic values can be handled by using correlation. Correlation is the process of capturing dynamic values in a script and storing them in a variable. The variable can then be used in subsequent requests to ensure that the correct value is passed.

8.      How to debug a LoadRunner script?

Answer: LoadRunner provides several ways to debug a script, including adding debug statements, using the built-in debug options, and viewing the run-time data. You can also use the VuGen's integrated development environment (IDE) to step through the script and view the values of variables at different points in the script execution.

9.      What is throughput in LoadRunner?

Answer: Throughput in LoadRunner is a measure of how much data is transferred over a period of time. It is typically measured in bytes per second or bits per second and can be used to determine the amount of traffic a system can handle.

10.   What are the most common protocol used in LoadRunner?

Answer: The most common protocols used in LoadRunner are HTTP, HTTPS, Web Services, and Remote Control. However, LoadRunner also supports other protocols such as FTP, Oracle NCA, SAP, and Siebel.

11.   What are the different types of recording modes in LoadRunner?

Answer: LoadRunner offers three types of recording modes: GUI (Graphical User Interface), API (Application Programming Interface) and TruClient. GUI mode records the user's actions on the web interface, API mode records the communication between the client and server, and TruClient mode records the client-side activity, such as mouse clicks and keystrokes.

12.   How do you handle authentication in LoadRunner?

Answer: Authentication in LoadRunner can be handled by recording the login process and then parameterizing the script to use different user credentials during the load test. Alternatively, we can also use "web_set_user" and "web_set_password" functions to set the user name and password in the script manually.

13.   How do you handle SSL certificates in LoadRunner?

Answer: To handle SSL certificates in LoadRunner, you can use the "web_set_sockets_option" function to enable SSL in the script. You can also import the SSL certificate into the LoadRunner's certificate store, so that it is recognized during the load test.

14.   How do you handle dynamic URLs in LoadRunner?

Answer: To handle dynamic URLs in LoadRunner, you can use the "web_reg_save_param" function to capture the dynamic value in the script and then use it in subsequent requests. Alternatively, you can also use "web_url" function to pass the dynamic values to the script during runtime.

15.   How do you handle dynamic correlation in LoadRunner?

Answer: Dynamic correlation in LoadRunner involves capturing the dynamic values in the script and using them in subsequent requests. The process includes identifying the dynamic values, capturing them using web_reg_save_param or web_reg_save_param_ex, and then using the values in subsequent requests using web_reg_save_param or web_reg_save_param_ex.

16.   What are the different types of actions in LoadRunner?

Answer: LoadRunner has two types of actions: "transactions" and "rendezvous points". Transactions are used to measure the response time of a specific action, such as login or search. Rendezvous points are used to simulate concurrent users performing the same action at the same time.

17.   How do you parameterize data in LoadRunner?

Answer: Parameterization in LoadRunner involves replacing hard-coded values in the script with variables. This can be done using the "web_reg_save_param" function to capture dynamic data and then using the captured values in subsequent requests. You can also use Data-Driven Testing (DDT) to parameterize data by reading it from an external source like a CSV or Excel file.

18.   How do you handle dynamic data in LoadRunner?

Answer: To handle dynamic data in LoadRunner, you can use correlation techniques to capture the dynamic values in the script and then use them in subsequent requests. Additionally, you can use "web_reg_save_param_ex" function to handle dynamic data coming from dynamic arrays and tables.

19.   How do you handle cookies in LoadRunner?

Answer: Cookies in LoadRunner can be handled by using the "web_set_cookie" function to set the cookies in the script, and the "web_add_cookie" function to add the cookies to the requests. Additionally, you can also use "web_cleanup_cookies" function to clear the cookies before the test runs.

20.   What is the role of the LoadRunner controller?

Answer: The LoadRunner controller is responsible for managing the execution of the load test. It allows you to set the number of virtual users, the scenario, and the duration of the test. The controller also allows you to view the test progress, monitor resource usage, and generate reports. It also allows you to distribute the load across multiple load generators.

21.   How do you configure load generators in LoadRunner?

Answer: To configure load generators in LoadRunner, you need to install the LoadRunner Agent on each machine that will act as a load generator. Once the agent is installed, you can configure the load generator settings in the controller by specifying the number of virtual users that each load generator should run, the IP address of the load generator, and the scripts that should be run on that load generator.

22.   What is the difference between LoadRunner and Performance Center?

Answer: LoadRunner is a standalone performance testing tool, while Performance Center is an enterprise-level performance testing solution. Performance Center provides additional features such as centralized management of load generators, distributed load testing, and integration with other testing tools. It also provides more advanced reporting and analysis capabilities.

23.   How do you troubleshoot LoadRunner scripts?

Answer: To troubleshoot LoadRunner scripts, you can use the built-in debugging options, such as adding debug statements, viewing the run-time data, and using the VuGen's integrated development environment (IDE) to step through the script. You can also use the "web_get_int_property" and "web_get_string_property" functions to check the values of variables at different points in the script execution.

24.   How do you integrate LoadRunner with other testing tools?

Answer: LoadRunner can be integrated with other testing tools, such as JIRA, HP Quality Center, and Jenkins, using the LoadRunner API.