Outperform With Our Performance Testing Interview Questions and Answers

Introduction

If you're aspiring to excel in performance testing or aiming to advance your career, it's crucial to be well-prepared for performance testing interviews.

To help you in this endeavor, we have compiled a comprehensive guide featuring frequently asked advanced performance-testing interview questions. You can gain all the necessary skills from performance testing training and certification. These performance testing questions cover a wide range of topics that interviewers typically ask to evaluate the skills and qualifications of performance testing professionals.

Q1. What Do You Understand About the Regular Expression Tester?

Ans- As a post-processor, this element executes after each sample request in its scope, applying the regular expression; extracts the requested values, generating the template string; and finally stores the result into a given variable name, which can be referenced further down the test plan. To fully maximize the use of the Regular Expression Extractor post-processor, it helps to get acquainted with regular expressions in general. The RegExp Tester view is one of the options you can choose from the View Results Tree listener dropdown menu items. It allows you to test various regular expressions against the server response on a per-sampler basis. 

When you are interested in extracting a variable or group of variables that vary dynamically based on which thread is executing, this gives you the maximum flexibility to test and tune your regular expression until you find the match that suits your needs. Such an element is necessary for a significant amount of time to be spent nailing down the suitable pattern matcher, as it would involve rerunning your test plan several times with various inaccurate expressions, hoping it eventually matches.

Q2. What Do You Understand by the Debug Sampler?

Ans- The debug sampler generates a sample containing all the values of JMeter variables and properties. A View Results Tree listener must be present in the test plan to view its results. This nifty component helps you debug your test plans appropriately, providing the tools to analyze the runtime-assigned values of various variables during test execution. In our example above, suppose we added a Regular Expression Extractor post-processor to the /iTunes/charts sampler and stored it in a variable. We can view the value assigned to the variable and, more importantly, how to get to the different values if there is more than one match. To add a Debug sampler, right-click on Thread Group and navigate to Add | Sampler | Debug Sampler.

Q3. What Do You Understand By Using Timers in Your Test Plan?

Ans- By default, JMeter doesn't put timers in your test plans when a scenario is recorded. This phenomenon is far from reality. Ideally, users will think or wait time between page views and requests. Getting JMeter to simulate such pauses or waits makes your test plans more realistic, bringing them closer to how actual users might behave. JMeter offers various built-in timer components that help achieve this. Each varies from the others in how it varies the simulated pauses. The following is a list of included timers as of the time of writing. 

• The Constant timer: The Constant timer is used if you want each thread to pause for the same time between requests.
• The Gaussian random timer: The Gaussian random timer pauses each thread request for a specific time, with most intervals occurring near a particular value. The total delay is the sum of the Gaussian distributed value times, the value specified, and the offset.
• The Uniform random timer: The Uniform random timer pauses thread requests for a random amount of time, with each interval having the same probability of occurring. The total delay is the sum of the random and offset values.
• The Constant throughput timer: The Constant throughput timer introduces variable pauses calculated to keep the total throughput, samples per minute, as close as possible to the targeted figure. Though called a constant throughput timer, the throughput can be varied using a counter value, JavaScript value, BeanShell value, or remote BeanShell server.
• The Synchronizing timer: The Synchronizing timer helps simulate large instantaneous loads on various points in the test plan by blocking threads until a certain number of threads have been blocked, then releasing them all at once.

Q4. What is Flood.io?

Ans- Flood.io is a service that removes the pain of setting up and maintaining a cloud-based load and the performance test infrastructure. It can be found at IUUQGMPPEJP. With Flood.io, you upload an already recorded test script to its service, and it takes care of the rest, ensuring that your tests are distributed among several machines while assembling significant results and metrics in a beautiful and well-crafted UI in real-time as the test progresses.

Q5. What Do You Understand by BlazeMeter?

Ans- BlazeMeter is a cloud testing service described as a load-testing cloud. It aims to get you up and running with distributed testing in no time. Their platform allows you to test and monitor mobile and web applications under heavy and realistic loads while presenting you with valuable metrics and reports. It is a paid service, but they do offer a free account that we will be using for this section. The free account allows you to simulate at most 50 users for a maximum of 1 hour, which is sufficient to get a feel of the service.

Q6. What Are The Benefits of LoadRunner on Testing Tools?

Ans- Benefits of LoadRunner testing tools are:

• Versatility
• Test Cases Results
• Easy Integrations
• Robust reports
• Enterprise Package

Q7. What are The Key Elements to Consider During Performance Testing?

Ans- These elements should be considered during performance testing:

• The reasons for failure
• The difference in the measurements with previous test results.
• New actions defined that are responsible for performance change
• Make sure to document every test result for better analysis.
• Recommended points to include in the result document are:

Q8. What Are Concurrent User Hits in The Load Testing?

Ans- The number of users who requested/accessed the server and successfully processed their requests until an inevitable change is observed in the performance. In general, performance degradation exists while the number of users trying to access concurrently as the load increases.

Q9. What is Spike Testing in Performance Testing?

Ans- Spike testing is a performance testing method where a system is applied with a drastic change in the user base and load on the application to test the performance. Spike testing helps you find whether a system can handle the drastic changes that occur on the application when there is a sudden increase or decrease in the user base of its operations.

Q10. What are The Features of JMeter?

Ans- Here are some of its features:

• Performance test of different server types, including web (HTTP and HTTPS), SOAP, database, LDAP, JMS, mail, and native commands or shell scripts
• Complete portability across various operating systems
• Full multithreading framework allowing concurrent sampling by many threads and simultaneous sampling of different functions by separate thread groups
• GUI (Graphical User Interface)
• HTTP proxy recording server
• Caching and offline analysis/replaying of test results
• Highly extensible
• Live view of results as testing is being conducted

JMeter allows multiple concurrent users to be simulated on the application, allowing you to work towards most of the target goals mentioned earlier in the chapter, such as attaining a baseline, identifying bottlenecks, etc. Learn more about Jmeter and explore it from Jtmeter tutorials from online sources. 

Q11. What is the Difference Between JMeter and SOAPUI?

Ans-

JMeter	SoapUI
It is used for load and performance testing HTTP, JDBC, JMS, Web Service(SOAP), etc.	It is specific for web services and has a more user-friendly IDE
It supports distributed load testing	It does not support distributed load testing. Most IDE has plugin support

Q12. Why Does JMeter Become a Natural Choice of the Tester When it Comes to Performance Testing?

Ans- JMeter tool has benefits like: 

• It can test static resources like HTML and JavaScript and dynamic resources like Servlets, Ajax, JSP, etc.
• JMeter determines the maximum number of concurrent users your website can handle.
• It provides a variety of graphical analyses of performance reports.

Q13. What Are The Important Performance Testing Tools?

Ans- Know the importance of performance testing tools and why choosing the right performance testing tools is important. 

• HP Loader
• HTTP Load
• Proxy Sniffer
• Rational Performance Tester
• JMeter
• Borland Silk Performer

Q14. What are The Common Mistakes Committed During Performance Testing?

Ans- Here are some mistakes committed during performance testing:

• Unknown or unclear non-functional requirements provided by the business.
• Unclear workload details
• Directly jumping to multi-user tests
• Running test cases for a small duration
• Confusion on an approximation of the concurrent users
• Difference between the test and production environments
• Network bandwidth is not stimulated properly
• No clear base-lining of the system configurations

Q15. What Are Some of the Best Tips for Conducting Performance Testing?

Ans- The following are some of the best tips for conducting performance testing:

• The test environment should mirror the production ecosystem as much as possible. If there are any deviations, then the test results may not be accurate and cause problems when the application goes live.
• It is preferred to have a separate environment dedicated to performance testing.
• The tools selected for testing should automate our test plan as best as possible.
• Performance tests should be run several times to obtain a consistent, accurate performance measure.
• The performance test environment should remain the same in between the testing process.

Conclusion

Looking out for a job in Performance Testing can sometimes be daunting, especially if you are new to the field. It's essential to prepare for your Performance Testing interview so you can make the best impression possible. That is why we have compiled some of our top Performance Testing interview questions and answers to help you ace your following interview. You can also check out other trending QA Online Courses to help learners understand the core concepts of Software Testing and Excel as a QA specialist. Get familiar with software testing tools from top industry experts with online certification courses for quality assurance.