Performance Testing Interview Questions

If you're looking for Performance Testing Interview Questions for Experienced or Freshers, you are in the right place. There are a lot of opportunities from many reputed companies in the world.

Mindmajix as a team has got enough questions from the trainees who got their Performance Testing Training and cracked interviews at various MNCs around the world and successfully placed. From the collection of Performance Testing Interview questions, the following are the most common questions we got are listed to make it easy for those who are willing to crack the interview with ease.

We have categorized Performance Interview Questions - 2023 (Updated) into 2 levels they are

• Performance Engineering
• Performance Testing

Top 10 Frequently Asked Performance Testing Interview Questions

1. What is the need for doing a performance test?
2. Mention the various types of performance testing?
3. Mention the tools that are used for doing performance testing?
4. How to correlate and parameterization in load runner?
5. What are the sub-genres of the performance test?
6. Define performance tuning?
7. Name the phases of the performance test?
8. Mention the phases of the life cycle of testing?
9. Differentiate between baseline testing and benchmark testing?
10. What is desktop testing?

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Performance Engineering Interview Questions 

1) What is the need for doing a performance test? 

In order to evaluate performances that are applications based we need performance testing. These evaluations are performed under certain stress and load conditions. The response time that is related to the activity of users is generally used for measuring performance testing. The entire system is tested at a high condition of stress and load. 

2) Mention the various types of performance testing?

There are three types of performance testing which are listed below. 

1. Load performance testing: This type of testing is utilized when the user wants to analog to testing that is volume-related. And it is also used for determining how to do application work with a huge amount of data. 
2. Stress performance testing: Applications are examined on the basis of their behavior during peak activity bursts. 
3. Capacity performance testing: The entire capacity of the system is measured and also it helps in detailing at what time the response time will become unacceptable. 

3) Mention the tools that are used for doing performance testing?

These are the best tools for performance testing. 

• QA Load (Compuware): This type of tool is used for performing load tests of database, web, and also a Char-based system. 
• Load Runner (HP): This type of tool is used for the web and various other kinds of applications. Various kinds of platforms, database and application environment is provided by this. In order to do an evaluation of the measurements of the performance of every component and also to the acknowledgment bottlenecks, it is used. 
• Web load (Rad view): This tool is used for comparing test metrics and running tests. 
• Rational performance tester (IBM): In order to identify the causes and presence of the performance system this tool is used.
• Silk performer (Borland): Predictions of the behavior of e-business can be done with the help of this tool. These predictions are made before the deployment is done. And also the predictions are made with the concerns of complexity and size. 

4) How to correlate and parameterization in load runner?

Correlation is done for the dynamic values or the values returned from the server for any request. Parameterization differs from correlation, in which the former takes care of static data which is usually entered by the user.

• Dynamic values: The value defined by the server for example sessions ids, session states and date values, and so on
• Static values: The values entered by users like passwords, usernames, and card details, etc

5) What are the sub-genres of the performance test? 

The sub-genres are described below. 

• Load testing: The performance testing that is done in order to examine applications' performance that is based on a load that is specified and expected is termed as Load testing. The increment of load can be done by increasing the quantity of user who is performing a specified work within a specified time limit. 
• Volume testing: This test is performed in order to find the quantity of data that can be handled effectively and efficiently by a system.
• Stress testing: this test is performed in order to make an evaluation of the performance of the system by increasing the number of users than the requirements. This is done in order to check at which level the application might crash. 
• Spike testing: This test is used to sterling what will happen if suddenly there is a huge increase or decrease in the number of users of the application system. 
• Soak testing: When there is a great deal of load for a long time on the application system then soak testing is performed to determine the behavior of the application in terms of response time and stability. 

6) Define performance tuning?

In order to make improvements in the performance of the system performance tuning is used and there are two types. 

1. Hardware tuning: To replace, add or optimize components of hardware of the application system this kind of tuning is utilized. And also to make improvements in the performance of the system, changes are done with the help of hardware tuning on the level of infrastructure. 
2. Software tuning: This tuning is helpful when it comes to identifying the bottlenecks of a software level. These identifications are done with the help of profiling the database and code. With the help of this tuning, modifications are made to the software in order to rectify the bottlenecks. 

7) What do you mean by concurrent user hits in case of load test?

There may arise a situation when more than one user will hit on the same event of the application during load testing and this situation is referred to as concurrent user hit. There is the addition of these concurrency points. This is done so that the virtual multiple users would be able to work in a single event of application. 

8) Why do the users need to do performance testing? 

Performance testing is a very good platform because of the following reasons. 

• It is used to verify the application's response time for the user's numbers which is intended. 
• It also provides the capacity of load testing of the application to its maximum level. 
• It also provided the facility for managing the transaction quantity. 
• Under both the unexpected and expected load of the user, application stability is provided. 
• It also makes sure that response time is provided to the users properly during production. 

9) Mention the reasons why load testing in the automated form is performed?

There were certain disadvantages of Manual load testing which are described below.

• There was no accuracy regarding the measurements of the application's performance. 
• It was also very difficult to perform synchronization among users. 
• Also, there is a need for the number of users in real-time in case of performance testing. 
• Also, manual testing will cause an increment in the cost of infrastructure. 
• Due to these above-mentioned disadvantages of load testing in the form of manual procedures, automated testing is performed. 

10) In the case of performance testing, mention the entering and exiting criteria.

The starting of performance testing is done at the design level only. After the testing is done, results are collected, and later they are analyzed in order to make improvements regarding the performance. During the whole process of life cycle development, performance tuning is done and the factors on which it is based are scalability and reliability during the presence of the load, application release time and tolerance criteria of performance and stress. 

11) How is it possible to identify situations related to performance bottlenecks?

Through the process of monitoring applications that go against the stress and load conditions, bottlenecks can be identified. Also, there is the requirement of load runner. Load runner is required since various kinds of monitors are provided by it that of the monitor of the web resource, firewall monitor, runtime monitor, database server, and network delay. 

12) List the activities which are performed during performance testing?

The activities are:

• Creation of user scenarios 
• Distribution of users 
• Scripting 
• Application dry run 

Implementation of the load test, the collection of results, and then analysis of results

13) What is JMeter?

It is another java tool that is used for performance load testing. It can analyze and measure the performance of a variety of services with a focus on a web application. Its architecture is based on plugins. The last version of Apache JMeter is 3.3. we can also run JMeter with Jenkins.

14) Mention the steps required in JMeter to create a performance test plan. And explain how one can execute Spike testing in JMeter? 

In order to create a performance test plan in JMeter

• Add thread group 
• Add JMeter elements 
• Add Graph result
• Run the test and get the result 

 In JMeter, Spike testing may have been done by using the Synchronizing timer. The threads are jammed by synchronizing the timer until a certain number of threads have been clogged and then released at once, creating a large instantaneous load.

15) What are the common mistakes that are done during performance testing? 

The common mistakes that are generally committed during Performance Testing are:-

• Direct jump to multi-user tests 
• Test results not validated 
• unknown workload details 
• Too small run duration 
• Lacking long-duration sustainability test 
• Confusion on definite of Concurrent users
• a significant difference between test and production environment 
• Network bandwidth not stimulated
• Underestimating performance testing schedules
• Incorrect extrapolation of pilots 
• Inappropriate base-lining of configurations.

16) List out some common performance bottlenecks?

Some common performance bottlenecks include:

• CPU Utilization
• Memory Utilization
• Networking Utilization
• S limitation 
• Disk Usage

17) What is Neo load?

Neo load is a tool by which the performance of the web or mobile application is measured. It is a stress and load testing tool. It provides programmatic solutions to the developers to help them optimize the performance before the application goes into production. It is available in French and English. It's a type of load testing tool

39) What is the throughput?

While lead testing, the amount of requests handled by the server or the amount of data served by the application per defined time gives a throughput of the application. Throughput is defined in different ways, like bits per second, reports per year, requests handled per day, etc. 

40) What is the protocol?

The method of executing predefined instructions in order to make two systems interact or information exchange is defined as protocol. Protocols are recommended to improve the load and performance handling of the application.

41) What is stress testing in performance testing?

In order to know the system performance when the load is maintained consistently at the system’s upper limit of maximum capacity, the performance results are analyzed to know how far the resources can sustain the upper limit with good performance as expected.

42) What is Soak testing in performance testing?

Expecting a continual increase in the load, system resources are monitored with their performances getting affected with load increase. In the due course of the time any data leak is monitored and the memory management is observed to make sure, performance does not affect any of the memory constraints and no data loss happens.

43) What is the Spike testing in performance testing?

Spike testing is used to test the performance of the system when the number of users keeps on increasing with a large number with the same resources available to serve the number of users. This will help to understand how many users can the system successfully handle their requests without loss in its performance or any issues.

44) What is the Benchmark in performance testing?

It is a kind of load testing performed on part of the application of complete application with the varied load to monitor performance changes. It is repeated until there exists a very minor percentage of difference in the measurements noted from the earlier tests.

45) What are the baseline tests?

It is a method of verifying or validating the reports submitted by performance testers that need to be addressed by developing a team. A baseline test is done before any action to be taken to improve the performance that was observed low while testing. On successful completion of baseline tests, more than eighty percent of the issues can be recovered.

46) List some commercial testing tools?

Silk Performer, QALoad, WebLoad, LoadRunner, Rational Performance Tester are few testing tools by various providers.

47) What are concurrent user hits in the load testing?

It is the number of users who requested/accessed the server and got successfully processed their requests until there is a certain change observed in the performance. In general, there exists performance degradation while the number of users trying to access concurrently as the load increases.

48) How can you identify performance test use cases for any application?

Testing is done to measure the performance of every action performed. And these actions have to be noted that will help you engineer the performance. There exist certain measures to be considered while monitoring these performance tests, like users have to be working on the core functionality of the application, trying to perform operations on databases like CRUD, and the number of users trying to concurrently access the application should be more. With all these criteria, even manual test cases can help you in identifying the performance measurements.

49) Differentiate performance testing and performance engineering?

The process of identifying the issues that disturb the performance of any application is performance testing whereas, improving the performance of the application by observing the measurements got from the performing testing by necessary changes in terms of architecture, resources, implementation, etc is performance engineering.

50) What is spike testing in performance testing?

Spike testing is a method of performance testing 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 their operations.

51) What are the key elements to consider while performance testing? 

• Reasons for failure
• The difference in the measurements with previous test results.
• New actions defined that is responsible for performance change
• Make sure to document every test result for better analysis.
• Recommended points to include in the result document are:
  • Aim behind test
  • Number of users
  • Scenario used
  • Time is taken to complete the test
  • Throughput
  • Response time
  • Graphs and their changes with earlier reports
  • Possible errors
  • Error detected
  • Recommendations