JMeter Interview Questions and Answers
Q1. What is JMeter device?
Ans: Apache JMeter is open source software, a a hundred% pure Java laptop application, designed to load take a look at practical behavior and measure performance of net web sites. It was at first designed for load trying out internet packages however has because expanded to different take a look at features
Q2. What is the which means of throughput in JMeter?
Ans: Throughput is one of the important performance indicator whilst evaluating the utility overall performance. It indicates number of transactions or requests that may be made in a given time frame. It is a useful size to check the burden potential of the server.
Q3. What is latency in Jmeter?
Ans: In easy phrases, Latency is community postpone (time taken by using community whilst shifting statistics) In JMeter latency is time among, when request is despatched to server until first byte of reaction reaches the consumer/Jmeter. If response time may be very low sufficient then you definately wont get specific degree of latency.
Q4. Why have to we pick JMeter tool for overall performance checking out?
Ans: The benefits of using JMeter tool for perofrmance testing are:
It is free to use with zero licensing fee.
It is open source, anybody can customise it for his or her precise use.
It has suitable on line network aid and tutorials.
It helps overall performance trying out of smart style of applications rangin from websites, internet offerings to FTP and Databases.
It is easy to learn and use.
Q5. What is a thread organization in JMeter?
Ans: A Thread Group is an element of JMeter test plan that represents a pool of virtual users acting a set of operations.
Q6. What is Performance Testing?
Ans: Performance trying out is a non-functional trying out in which software's performance is evaluated underneath predicted or better load. It is executed earlier than the utility is deployed on manufacturing to make certain that it does not crashes and responds within popular/acceptable time at real load.
Q7. What are a few capabilities of JMeter?
Ans: Some of the features of JMeter are:
JMeter is one hundred% Java primarily based. So, it has all the blessings of Java primarily based packages like portability, extensibility, robustness and so forth.
It has record and play returned characteristic that guarantees smooth and rapid introduction of take a look at scripts.
It presents extraordinary listeners to seize and analyse the check outcomes in both tabular and graphical format.
It can be used to load check one of a kind protocols- HTTP, HTTPS, FTP, LDAP, TCP and so on.
Q8. What form of programs can be tested the usage of JMeter?
Ans: The different varieties of packages that may be examined using JMeter are:
Web offerings both - REST and SOAP
SMTP, POP3, IMAP
Q9. Explain parameterization in JMeter?
Ans: Parameterization is technique of parameterizing the consumer enter or other take a look at inputs, on the way to use different values for unique users and loops iterations. Example - an outside csv file can be created with more than one login credentials after which surpassed to the burden test script to be able to fetch exclusive credentials for each iterations. [For more details, refer to the post- Parameterization in JMeter]
Q10. What are the different sorts of Performance Testing techniques?
Ans: The exclusive types of overall performance checking out are:
Load Testing - Type of performance trying out to measure the utility behaviuor beneath predicted workload.
Stress Testing - Evaluating application's behaviour underneath load better than utility's threshold or top load situations.
Endurance Testing - Testing application under extended load check, commonly used to stumble on reminiscence leaks in utility.
Spike checking out - Evaluating utility's behaviour on unexpected increase within the range of customers.
Volume checking out - Testing the utility with massive amount of statistics(usually with large facts of records within the database).
Q11. What all sports are accomplished at some stage in performance trying out of any application?
Ans: Activities done for the duration of overall performance testing:
Performance Test Requirements Gathering & Analysis - In this phase, all of the details about the software are gathered from the consumer and other stakeholders of the utility.
Testing Tool Selection - This section includes choice of the overall performance check tools.
Performance Tests Planning - The take a look at planning section includes strategizing the complete performance testing technique, infrastructure and environment setup; use case scenarios to be scripted and so on.
Test Script Implementation - In this section, the overall performance take a look at scripts are created using the tool decided on within the previuos levels.
Performance Test Execution - In this phase, the test script are achieved for a predefined time specified all through the planning phase.
Test Result Analysis - The end result analysis section includes consolidating the test results for figuring out the one-of-a-kind performance attributes of the application and finding the performance bottlenecks.
Q12. What is correlation?
Ans: Correlation is the maximum crucial thing of scripting in JMeter. It includes fetching dynamic data from preceding requests/calls and passing them to the following requests as parameters. Example - we can extract the values of consultation variables from the reaction of the request with login information and then bypass the ones values to the subsequent requests (accordingly coping with the periods). [For more details, refer to the post- Correlation in JMeter]
Q13. What is a Rendezvous Point?
Ans: The Rendezvous factor in JMeter is used to carry out spike checking out. It is carried out the usage of "Synchronizing Timer" by waiting till the range of energetic users attain a certain targeted value for the duration of the burden test.
Q14. What are assertions in JMeter? Explain the available assertions in JMeter.
Ans: Assertions in JMeter are used for verification of positive values inside the reaction of Samplers requests. The commonly used assertions are - response assertion, size announcement, XML assertion,beanshell declaration, HTML Assertion, XPath statement and so on.
Q15. What is a Test plan?
Ans: A Test plan in JMeter is a logical container that consists of all the take a look at factors which drives the overall performance test. Some of the special factors in a take a look at plan are - Thread Group, Samplers, Timers, Assertions, Listeners etc.
Q16. What is a Workbench?
Ans: A Workbench in JMeter is a brief region of garage for the test factors. It additionally consists of non-test elements like HTTP Proxy Server, which can be configured to record scripts through browser in JMeter. Any detail placed in workbench doesn't get stored after with the testplan's jmx script.
Q17. What is ramp up period?
Ans: At the beginnning of load check of an application in preference to setting all the users live, we slowly ramp up the quantity of users that allows you to study their effect inside the application's performance. In JMeter ramp-up duration defines the time period within which the all the detailed customers get in going for walks state.
Q18. What are samplers in JMeter?
Ans: Samplers are used for sending specific sorts of requests to the server. Some of the commonly used samplers are - HTTP Request, JDBC Request, SOAP-XML Request, JUnit request, TCP Sampler and many others.
Q19. What are Listeners in JMeter? State a number of the broadly used Listeners?
Ans: Listeners are used for viewing, saving of take a look at outcomes and also assist in tabular and graphical evaluation of the test consequences. Some of the extensively used Listners are - Aggregate Report, Aggregate Graph, Graph Results, View Results Tree and so forth.
Q20. What is distributed load checking out? How can it be done in JMeter?
Ans: Distributed load checking out is the procedure using which multiple systems can be used for simulating load of large quantity of users. The cause of using multiple gadget for load checking out is the challenge of single gadget to generate huge range of threads (customers). In JMeter we can do disbursed load testing the use of the grasp slave configuration. [For complete steps to perform distributed load testing refer to the post- Distributed load testing in JMeter]
Q21. What are the one of a kind timers in JMeter?
Ans: Timers are used for halting the check execution of a thread for a positive predefined time. These timers are used for simulating the actual person think time. The exclusive types of timers available in JMeter are - Constant Timer, Gaussian Random Timer, Uniform Random Timer, Constant Throughput Timer, Synchronizing Timer, Beanshell timer, BSF Timer and so on.
Q22. What is the use of Configuration factors?
Ans: Configuration elements are used for customizing the sampler requests e.G. CSV Data Set Config may be used for parameterizing the sampler requests with values fetched from outside csv file.
Q23. What are Pre-Pocessors?
Ans: Pre-processors are check plan factors which can be achieved before the sampler request execution. Some generally used pre-processor in JMeter are BeanShell PreProcessor, HTML Link Parser, HTTP URL Re-writing Modifier, RegEx User Parameters and many others.
Q24. What are Post-processors?
Ans: Post-processors are the test plan elements which might be performed after the sampler request execution. Generally put up processors are used for fetching a few values from the sampler reaction.
Q25. How can we lessen the aid requirement in JMeter?
Ans: To make the best out of the available sources and in general as a exercise, following practices have to be incorporated within the checks:
Use non-GUI mode: jmeter -n -t test.Jmx -l take a look at.Jtl
Use as few Listeners as possible; if the usage of the -l flag as above they can all be deleted or disabled.
Don't use "View Results Tree" or "View Results in Table" listeners at some stage in the burden take a look at, use them best for the duration of scripting segment to debug your scripts.
Rather than the usage of plenty of comparable samplers, use the equal sampler in a loop, and use variables (CSV Data Set) to vary the sample. Or perhaps use the Access Log Sampler. [The Include Controller does not help here, as it adds all the test elements in the file to the test plan.]
Don't use JMeter's functional mode at some stage in the burden test executions.
Use CSV output as opposed to XML.
Only save the facts which you need.
Use as few Assertions as possible