Performance Testing Interview Questions

In the current times, once the development of the application or software is completed, testing is one of the important phases which is focussed on. To ensure that the customers or the users are satisfied with the application, without any delay, errors, or wait time, it is crucial to test the application and check if the functionality is working as expected. If the application is not tested, you will lose the customers with negative feedback and customer dissatisfaction. By this, you might have an idea of how testing is important. Every organization will maintain testing teams, holding a bunch of opportunities for the individuals for both freshers and experienced who are trained and certified in the subject. In this article, you will review the Performance testing interview questions which will help you in grabbing the interview for the position being hired. Below are the most frequently asked performance testing interview questions that are curated by experts. Let’s get started.

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Q1) What do you know about performance testing? List out the different types of testing in performance testing?

Ans: Performance Testing is referred to as a type of software testing that allows the developers and testers to ensure that the application is working as expected under the workload. The primary goal of performance testing is not only to detect or find the bugs but also to eliminate performance bottlenecks. The performance testing includes the quality attributes of the system which will be measured.It is referred to as a type of testing that focuses on ensuring the parameters like the Swift Response, Stability, and Reliability under different replicated real-time events.

The performance testing is of three different types which are listed below. 

1. Stress performance testing:  In stress performance testing, the primary focus is to test the applications based on the behavior whenever there is a workload or during the peak activity bursts.

2. Capacity performance testing: Incapacity performance testing, the entire capacity of the system will be measured. Apart from this, it also helps in detailing the timeframe at which the response time will become unacceptable. 

3. Load performance testing: The load performance testing is performed when the user wants to analog to testing which is volume related. Apart from this, it is also used to determine how an application works when there is a large amount of data. 

Q2) List out the different attributes that are included in the performance testing?

Ans: There are three different attributes that are included in the Performance Testing. They are::

Stability: This attribute helps us to determine if the application is working as expected and is stable enough when there are varying workloads.

Scalability:  This attribute helps us to determine the maximum user load that the software application is capable of handling.

Speed: This attribute helps us to determine whether the application is responding quickly or not.

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Q3) briefly give an idea about performance tuning?

Ans: Performance tuning is used to make the required changes or enhancements, or improvements in the performance of the system . There are two types of performance tuning. They are:

Hardware tuning: Hardware tuning is used whenever there is a need to  replace, optimize  or add the hardware components of the application system. It also helps in making the necessary improvements in the performance of the system, however, the changes will be done with the help of hardware tuning on the level of infrastructure. 

Software tuning: Software tuning is used whenever there is a need to identify or determine the bottlenecks of a software level. These identifications or determinations will be performed with the help of profiling the database and code. The required modifications will be made to the software in order to rectify the bottlenecks with the help of software tuning.

Q4) Briefly explain about the entering and exiting criteria in the performance testing?

Ans: The beginning of the performance testing will be performed at the design level only. Once the testing is completed, results will be collected and will then be analyzed in order to make the necessary improvements in the system regarding the performance. During this entire process of life cycle development, performance tuning is performed and, scalability and reliability are some of the factors on which it is based whenever there is a presence of the load, application release time, and tolerance criteria of performance and stress. 

Q5) What is the need of performance testing to be done by the users? 

Ans:

  • Performance testing is considered as one of the best platforms. Below are some of the reasons which would explain the significance of the performance testing.
  • The performance testing is used to perform the verification of the application's response time for the user's numbers. 
  • The performance testing also provides the flexibility to the users to identify the capacity of load testing of the application to its maximum level. 
  • The performance testing also helps in managing the transaction quantity. 
  • The performance testing also provides the application stability in both the versions of expected and unexpected load of the users.
  • Performance testing also ensures that the response time is provided as and when required to the users during the production. 

Q6) List out the different types of sub-genres of the performance test? 

Ans: The sub-genres of the performance test are explained below. 

Load testing: Load testing is the type of performance testing that is performed in order to review and check the applications' performance which is based on the load that is specified and expected.  The increment of load can be performed or implemented by increasing the quantity of users who are responsible for performing a specified task within a given specified time limit or deadlines

Volume testing: Volume testing is performed in order to determine the quantity of data that can be handled efficiently and effectively  by a system without any issues or concerns.

Stress testing: The stress testing  is performed in order to evaluate or check performance of the system by increasing the number of users than the requirements. This is performed in order to check the  level at which the application might get crashed. 

Spike testing: The spike testing is performed to check  what will happen if there is a huge increase or decrease suddenly  in the number of users of the application system. 

Soak testing: The soak testing is performed in order to determine or identify the behavior of the application in terms of response time and stability wherever there is a long time load on the application system that you are working.

Q7) Briefly explain about profiling in performance testing?

Ans: Profiling in performance testing is referred to as a procedure of pinpointing a bottleneck performance at miniature levels. The profiling is performed by presentation teams for manufacturing in which the developers and testers play a prominent role. You are allowed to profile in any application layer that is getting tested. If you are not willing to perform the application profiling, you will need to make use of the tools for performance profiling of application servers.

Q8) What are the common performance problems that are being faced by the users?

Ans: Below are the common performance problems that are being faced by the users.

  • Poor Scalability
  • Longer loading time
  • Poor response time
  • Bottlenecking (coding errors or hardware issues)

Q9) Why does JMeter become a natural choice of the tester when it comes to performance testing?

Ans: JMeter tool has come up with a list of benefits that are listed below:

  • JMeter tool can be used for performing the testing of both static resources, as well as dynamic resources. The static resources include  HTML and JavaScript while the dynamic resources include Servlets, Ajax, JSP, etc.
  • JMeter also comprises the tendency to identify the maximum number of concurrent users that the website is capable of handling.
  • It is also capable of providing you a variety of graphical analyses of performance reports.

Q10) What are the different steps involved in the Performance Testing Process?

Ans: There are different steps involved in the performance testing process. They are:

Right testing environment: You need to identify and figure out the physical test environment before getting into the performance testing, like hardware, software and network configuration.

Identification of the performance acceptance criteria: It comprises different constraints and goals for different parameters like response times , throughput, and resource allocation.

Planning and designing the Performance tests: In this stage, it is important to define how the usage is likely to vary among the different end users and also determine the key scenarios in order  to test for all possible use cases.

Test environment configuration: Before the execution is performed, , there is a need to prepare the testing environment and arrange the different  tools, other resources, etc.

Test design implementation: You will need to create a performance test based on the test design.

Run the tests: In this phase, execution and monitoring of the test cases takes place.

Analyze, tune and retest: In this phase, the analysis, consolidation and sharing of the test results takes place. Once these tasks are performed, fine tuning and testing takes place again to check if there is any enhancement or improvement in the performance levels. You will need to stop the test, if the CPU is causing any bottlenecks.

Performance Testing Interview Questions Loadrunner

Q11) List out some of the most commonly used  Performance Testing Tools.

Ans: There are many tools that are available in the market for test management, performance testing, GUI testing, functional testing, etc. It is recommended to opt for a tool which is on-demand, which is easy to learn based on your skills, generic and effective for the type of testing that you would like to do. Some of the common Performance Testing tools are:

  • LoadView
  • LoadUI Pro
  • Apache JMeter
  • NeoLoad
  • WebLoad

Q12) List out the different Parameters that are considered to do the Performance Testing?

Ans: Below listed are the parameters considered to do the performance testing:

  • Top waits
  • Processor usage
  • Bandwidth
  • Memory usage
  • Network output queue length
  • Memory pages
  • Response time
  • Committed memory
  • CPU interruption per second
  • Thread counts

Q13) Briefly explain about throughput in Performance Testing?

Ans: Throughput in simple terms, is referred to as the amount of data being transported to the server in response to the client request or based on the client request at a given or a specified time period. It can be calculated either in the form of requests per second, reports per year, hits per second, calls per day, etc. The performance of an application depends on the throughput value.  The performance of the application will be high if the throughput value is high.

Q14) List out some of the most common mistakes done in Performance Testing?

Ans: The common mistakes that will be done in Performance Testing are:

  • Direct jump to multi-user tests
  • Too small run duration
  • Network bandwidth not simulated
  • Unknown workload details
  • Lacking long duration sustainability test
  • Confusion on definition of concurrent users
  • Test results not validated
  • Underestimating performance testing schedules
  • Significant difference between test and production environment
  • Incorrect extrapolation of pilots
  • Data not populated sufficiently
  • Significant difference between test and production environment
  • Underestimating performance testing schedules
  • Inappropriate base-lining of configurations

Q15) Elucidate the differences between Baseline Testing and Benchmark Testing?

Ans: Baseline Testing: Baseline testing is referred to as the process of performing or running a set of tests in order to capture the performance information. When future changes are made in the application, this information will be used as a reference

Benchmark Testing: Benchmark testing is referred to as the method of comparing the performance of your system based on an industry standard that is set by another organization.

Q16.What is meant by a Protocol? List out some of the Protocols.

Ans: A protocol is defined as a set of various rules to establish the communication between the two or more systems for information.

Some of the most commonly used Protocols are :

  • HTTP
  • FTP
  • Web Services
  • HTTPS
  • Citrix

Q17) List out the different reasons behind the discontinuation of manual load testing?

Ans: There were certain drawbacks or limitations in manual Load Testing that has further led to the adoption of Automation load testing. Some of the reasons or limitations  are explained below:

  • It is found to be difficult to assess and recognize the  bottlenecks and outcomes.
  • The procedure to measure the performance of the application precisely is very complicated.
  • The overall infrastructure cost is increasing.
  • There is a Complexity in the  synchronization procedures between the two or more users.

Q18) Briefly list out the different activities that are involved in Performance Testing?

Ans: The activities that are involved in Performance Testing are:

  • Requirement gathering
  • Selection of the tools
  • Performance test plan
  • Performance test development
  • Performance test modeling
  • Test Execution
  • Analysis
  • Report

Q19) Briefly explain the differences between the Correlate graph and the overlay graph?

Ans: Correlate graph: Correlate graph is referred to as the graph in which the Y-axis of the graphs are plotted against each other. After this, the Y-axis of the graph which is active is considered to be the X-axis of the graph that is merged. Therefore, the graph which was merged with the Y-axis of that graph becomes the Y-axis merged.

Overlay graph: The overlay graph is the graph that plots two graphs that contain the same x-axis. Left Y-axis in the merged graph will represent the current value of the graph. Right Y-axis shows the value of the Y-axis of the graph that was merged.

Q20) How are the steps validated in a Script?

Ans: Each and every step in the script is validated with the content on the returned page. A content check  is used to verify whether the specific content is available on the web page or not. There are two types of a content check that can be used in LoadRunner. They are:

Text Check: This checks for a text/string on the web page

Image Check: This step will help you in checking for an image on a web page.

Performance Testing Interview Questions For Experienced

Q21) What is NeoLoad?

Ans: Neo load is called as a  type of load testing tool. Neoload is responsible for measuring the  performance of the web or mobile application. It is also responsible for providing the programmatic solutions to the developers  in order to help them in optimizing the performance before the application enters into the production. It is available in  two languages, French and English as well.

Q22) Briefly explain what is a correlation?

Ans: Correlation is used in order to handle the dynamic values in a script. The dynamic values will be changing for each user action whenever an action is replayed by the same user or any other different user. The correlation takes care of these values and prevents them from failing during execution in both the cases.

Q23) How do you perform  Spike Testing in JMeter?

Ans: In JMeter, spike testing will be performed  by using Synchronizing Timer. The threads that are jammed by synchronizing the timer upto a specific number of threads have been successfully blocked, and then release them all  at once which will then be creating a large immediate load.

Q24) What is meant by the Modular approach of scripting?

Ans: In the Modular approach, the function will be created for each and every request such as login, logout, save, delete, etc. The modular approach provides more freedom to reuse the request and saves time. Using this approach, it is suggested to work with web custom requests.

Q25) Elucidate the differences between manual correlation and automatic correlation?

Ans: Manual Correlation: Manual Correlation allows you to identify the dynamic value, identify the unique boundaries of capturing the dynamic value, find out the first occurrence of dynamic value, writing the correlation function web_reg_save_param before the request being included in the first occurrence of dynamic value in its response.

Automated correlation: Automated correlation works on the basis of predefined correlation rules. The script will be played back and scanned for autocorrelation on failing. Vugen is responsible for identifying the place whenever the correlation rules work and correlating the value on approval.

Q26) How will you identify the performance bottleneck situations?

Ans: Performance Bottlenecks can be detected by ensuring that you keep monitoring the application against load and stress conditions. In order to detect the bottleneck situations in performance testing, the testers usually make use of the Load Runner because it  is flexible to provide the support to many different types of monitors like a network delay monitor, web resource monitor, firewall monitor, run-time monitor, database server monitor, ERP server resources monitor and Java performance monitor. These monitors in turn help the tester in establishing the condition which will cause an increase in the response time of the application. 

Q27) List out the different benefits of LoadRunner in testing tools?

Ans: Below listed are the benefits of LoadRunner are:

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

Q28) What is concurrent user load in performance testing?

Ans: Concurrent user load in performance testing is referred to as something when multiple users will hit any operation or functionality at the same time.

Q29) List out the different activities that are performed during performance testing?

Ans: The different activities performed during the performance testing are:

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

Q30) Elucidate the steps that are required in JMeter to create a performance test plan?

Ans: You will need to do the following steps in order to create a performance test plan in JMeter. They are:

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

Conclusion:

I am sure you have got an idea now about the frequently asked performance testing interview questions and you would be able to crack the interview. It is important for you to have a review of the tutorials to gain a better understanding of the concepts. As most organizations are looking for the expertized individuals who are in the Testing field, these will help you in attaining the best career. All the best!