LoadRunner Interview Questions

LoadRunner Interview Questions for Experienced

24) How do you configure the number of Vusers in LoadRunner?

While building scenarios, you may change the number of Vusers in the controller section area. In addition to this, there are numerous advanced choices in the controller area, such as Vuser ramp-up and ramp-down.

25) What exactly is a correlation?

Correlation is used in test scripts to cope with changeable variables. The dynamic values may vary based on each user activity (value changes when the same User performs the action again) or for other users (value changes when action is replayed with different users). In all cases, these variables are kept by correlation, guaranteeing that they do not degrade throughout execution.

27) What exactly is the scenario?

The scenario describes the events that will occur throughout each testing session. A scenario, for example, describes and controls the number of people to imitate, the actions to be taken, and the computers on which virtual users run their simulations.

28) How To Create A Scenario?

We must install a LoadRunner controller. Following that, we add the list of hosts (where the vuser script runs), vuser scripts (where the vuser executes), and vusers that run throughout the scenario.

29) How Does A Scenario Work?

To execute a simulation, open an existing scenario first - Set up the scenario - Configure the output directory - Run the scenario.

30) How many different sorts of scenarios are there in LoadRunner?

LoadRunner has two types of scenarios:

1. Manual Scenario
2. Goal-oriented Scenario

31) How do you handle SSL certificates in LoadRunner scripts?

To handle SSL certificates in LoadRunner:

• You need to configure the run-time settings to accept server certificates.
• For specific SSL certificates, you may need to install the required certificate on the Load Generator machines.
• You can disable SSL verification using the web_set_sockets_option("SSL_VERSION", "TLS"); function to specify the appropriate SSL/TLS version.

32) What is the difference between lr_param_sprintf() and sprintf() in LoadRunner?

lr_param_sprintf() is a LoadRunner-specific function that formats a string and stores it in a parameter, while sprintf() is a standard C function that formats a string and stores it in a buffer. The key differences are:

• lr_param_sprintf() automatically handles memory allocation for the parameter.
• lr_param_sprintf() is safer to use in LoadRunner scripts as it avoids buffer overflow issues.
• sprintf() requires manual memory management and can lead to buffer overflow if not used carefully.

33) What is the role of load generators in LoadRunner?

Load Generators are used to simulate virtual users and generate load on the system under test:

• Load Generators execute the Vuser scripts and send requests to the system.
• Multiple Load Generators can be distributed geographically to simulate users from different regions.
• They help in distributing the load to mimic a real-world scenario where multiple users interact with the application from various locations.

34) How can you handle dynamic correlation in LoadRunner when the server response contains multiple instances of the same value?

To handle dynamic correlation with multiple instances of the same value:

1. Use the web_reg_save_param() function with the ORDINAL parameter.
2. Set ORDINAL to "ALL" to capture all instances.
3. Use web_get_int_property() to get the count of captured values.
4. Iterate through the captured values using a for loop and lr_paramarr_random() or lr_paramarr_idx() to access specific instances.

35) How do you analyze bottlenecks in LoadRunner test results?

Bottleneck analysis in LoadRunner involves:

• Analyzing Response Time Graphs: Identifying which transactions have high response times.
• Monitoring Resource Utilization: Checking CPU, memory, and disk I/O for the application server and database servers.
• Using Performance Monitors: LoadRunner allows the integration of monitoring tools like PerfMon, AppDynamics, or New Relic to identify slow services, queries, or endpoints.

36) Explain the concept of think time in LoadRunner and how it affects performance testing results.

Think time in LoadRunner simulates the delay between user actions in a real-world scenario. It's important because:

1. It makes the load test more realistic by mimicking actual user behavior.
2. It affects server resource utilization, as it allows the server to process requests and recover between actions.
3. It impacts concurrency levels and the number of virtual users required to simulate a given load.

Think time can be controlled using:

• lr_think_time() function
• Replay think time options in runtime settings (e.g., Ignore think time, Use recorded think time, Limit think time)

37) How does LoadRunner handle multiple test environments?

LoadRunner handles multiple test environments through Controller Scenarios:

• You can define multiple test environments by specifying different sets of Load Generators.
• The Scenario Scheduling feature allows you to simulate different environments by configuring ramp-up, ramp-down, and steady-state durations.
• LoadRunner also supports cloud-based load generators for running tests in diverse geographic regions.

38) What are rendezvous points in LoadRunner?

Rendezvous points in LoadRunner are synchronization mechanisms used to coordinate multiple virtual users (Vusers) to perform an action simultaneously. They help in:

1. Simulating sudden spikes in load on the system.
2. Testing the application's behavior under peak concurrent user actions.
3. Coordinating complex multi-user scenarios.

39) How does LoadRunner manage memory leaks?

LoadRunner can detect memory leaks by:

• Monitoring the system’s resource usage: LoadRunner’s Controller and Analysis components track memory usage over time.
• Running long-duration tests: By performing extended load tests, you can identify gradual increases in memory usage that may indicate leaks.
• Collecting and analyzing diagnostic data: Integrating LoadRunner with monitoring tools like Dynatrace or AppDynamics can help pinpoint the source of memory leaks.

40) How can you integrate external data sources into a LoadRunner script for data-driven testing?

To integrate external data sources in LoadRunner:

1. Parameter files:

• Create a CSV or Excel file with test data.
• Use Parameters List in VuGen to link the file.
• Access data using {parameter_name} syntax.

2. Database integration:

• Use lr_db_* functions to connect to and query databases. Example:

lr_db_connect("ConnectionString", "db1");
lr_db_query("db1", "SELECT * FROM users", "result");
lr_db_getvalue("result", 1, 1, "username");

3. XML files:

• Use lr_xml_* functions to parse and extract data from XML files. Example:

char *xml_file = lr_read_file("data.xml");
lr_xml_get_values("XML={xml_file}", "ValueParam=Name", "Query=/Root/User/Name", LAST);

4. Custom plugins:

• Develop C functions to read from specific data sources.
• Use lr_load_dll() to load the custom DLL in the script.

Choose the method based on data volume, format, and test requirements.

LoadRunner MCQ Questions

1. Which protocol is not supported by LoadRunner by default?

A. HTTP/HTTPS

B. FTP

C. WebSocket

D. MySQL

Answer: D. MySQL

2. What is the function of the ‘Think Time’ in LoadRunner?

A. To pause the execution of Vusers

B. To simulate the time between user actions

C. To create a delay between test execution steps

D. To measure response times

Answer: B. To simulate the time between user actions

3. Which of the following is a primary component of LoadRunner?

A. Controller

B. Analyzer

C. Vugen

D. All of the above

Answer: D. All of the above

4. What does parameterization help achieve in LoadRunner?

A. Simulate real-world scenarios by eliminating hard-coded values

B. Capture dynamic data from the server

C. Synchronize Vuser execution

D. Generate reports for test analysis

Answer: A. Simulate real-world scenarios by eliminating hard-coded values

5. What is the primary purpose of correlation in LoadRunner?

A. To record user actions

B. To handle dynamic values in responses

C. To measure throughput

D. To configure load generators

Answer: B. To handle dynamic values in responses

6. Which function is used to start a transaction in LoadRunner?

A. lr_start()

B. lr_start_transaction()

C. lr_transaction()

D. lr_begin_transaction()

Answer: B. lr_start_transaction()

7. What is a Load Generator in LoadRunner?

A. A machine that simulates user load

B. A tool to generate test reports

C. A monitor for system performance

D. A server that runs the application

Answer: A. A machine that simulates user load

8. What does the ‘Controller’ do in LoadRunner?

A. Records scripts for testing

B. Analyzes test results

C. Configures and manages load tests

D. Captures dynamic server responses

Answer: C. Configures and manages load tests

9. What are Rendezvous Points used for in LoadRunner?

A. To pause the script execution

B. To synchronize Vusers to perform tasks at the same time

C. To capture real-time data from the server

D. To start new virtual users during test execution

Answer: B. To synchronize Vusers to perform tasks at the same time

10. Which of the following monitors can be integrated with LoadRunner?

A. AppDynamics

B. New Relic

C. Dynatrace

D. All of the above

Answer: D. All of the above

Conclusion 

In this article, we learned about Loadrunner Interview Questions. LoadRunner is a powerful performance testing tool widely used to assess the scalability and reliability of applications under load. Mastering LoadRunner requires a strong understanding of its various components, such as Vugen, Controller, and Analysis, as well as the ability to effectively implement parameterization, correlation, and error handling in scripts.

To learn, see JCL Interview Questions, DNS Interview Questions, Operating System Interview Questions, and Power BI interview questions Basic.

Also read: Selenium interview question

Power Apps Interview Questions

Refer to our Guided Path on Code360 to upskill yourself in Data Structures and Algorithms, Competitive Programming, JavaScript, System Design, and many more! 

Do upvote our blogs if you find them helpful and engaging!