Interview Questions for a LoadRunner Performance Tester Role

Are you preparing for an interview for a LoadRunner Performance Tester role? Whether you're a fresher or transitioning into performance testing, it's essential to be well-prepared with fundamental concepts.

Here are 10 beginner-level interview questions that can help you ace your LoadRunner performance testing interview!

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1. What is LoadRunner, and what are its key components?

Answer:
LoadRunner is a performance testing tool by Micro Focus used to test applications under load. Its key components include:

• Virtual User Generator (VuGen) – Records and scripts user actions.

• Controller – Manages and schedules load tests.

• Load Generators – Generate virtual user load.

• Analysis – Provides test results and performance metrics.

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2. What is a Virtual User (VUser) in LoadRunner?

Answer:
A Virtual User (VUser) simulates a real user interacting with the application. Each VUser executes a script that mimics user actions like clicking buttons, entering data, or navigating pages.

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3. Explain the difference between load testing and stress testing.

Answer:

• Load Testing checks system performance under expected user load.

• Stress Testing pushes the system beyond normal capacity to identify breaking points.

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4. What protocols does LoadRunner support?

Answer:
LoadRunner supports multiple protocols, including:

• Web (HTTP/HTML)

• Java (RMI, JMS)

• .NET

• Database (SQL, ODBC)

• Citrix

• Mobile (HTTP Mobile, TruClient)

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5. What is correlation in LoadRunner, and why is it important?

Answer:
Correlation is the process of capturing dynamic values (like session IDs) from server responses and reusing them in subsequent requests. It ensures scripts run accurately by handling dynamic data.

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6. What are think times in LoadRunner?

Answer:
Think time is the delay between user actions (e.g., time taken to fill a form). It mimics real user behavior and can be adjusted in scripts for realistic load simulation.

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7. How do you analyze LoadRunner test results?

Answer:
The Analysis tool in LoadRunner provides graphs and reports on:

• Response times

• Throughput

• Hits per second

• Error rates

• Resource utilization (CPU, Memory, etc.)

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8. What is a rendezvous point in LoadRunner?

Answer:
A rendezvous point synchronizes VUsers to perform a specific action simultaneously, helping simulate peak load scenarios (e.g., 100 users logging in at the same time).

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9. What are the common performance bottlenecks identified using LoadRunner?

Answer:
Common bottlenecks include:

• Server-side issues (CPU, memory, disk I/O)

• Network latency

• Database bottlenecks (slow queries, locks)

• Application code inefficiencies

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10. How do you handle errors in LoadRunner scripts?

Answer:
Errors can be handled by:

• Using checkpoints (web_reg_find) to validate responses.

• Adding error handling functions (lr_error_message, lr_continue_on_error).

• Parameterizing dynamic values to avoid script failures.

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Final Thoughts

These questions cover the basics of LoadRunner performance testing and are great for beginners. If you're preparing for an interview, make sure to practice scripting, understand performance metrics, and explore real-world scenarios.

Got more questions? Drop them in the comments below! 🚀