JMeter is a JAVA tool, which is used for performance load testing.
JMeter acts like a group of users sending requests to a target server. Read the most frequently asked 35 top
JMeter Interview Questions and Answers for freshers and experienced pdf
JMeter Interview Questions and Answers List
1. What is the use of
Jmeter?
Jmeter is an open source desktop application software, 100% pure Java application, which is designed to perfom load testing of web based application.
Jmeter is used for different types of testing – Performance Testing, Functional Testing, Regression Testing, Unit Testing.
2. For what purpose Jmeter used?
Jmeter is a Performance Tool. It is used to test the performance of the application. Apache JMeter is a 100% pure Java desktop application designed to load test functional behavior and measure performance. It was originally designed for testing Web Applications but has since expanded to other test functions.
3. What do u sees when u opens a
JMeter?
By default,
Test Plan
Workbench
Can be seen
4. Is it mandatory to install java first, to run jmeter?
Yes, Jmeter is an java based application. So you should install java 1.5 or later version in your system.
5. Can we do regression testing with Jmeter?
Yes we can, after-all it is all about java-script.
6. How we can run jmeter?
By simply clicking on Jmeter.bat, or by using commnad: C:\>Jmeter
7. What are the options, do you see when jmtere window opens?
1. Test Plan
2. Workbench
8. What is Test Plan in Jmeter?
Test plan describes a series of steps JMeter will execute when run.
A complete test plan will consist of one or more Thread Groups, logic conrollers, sample generating controllers, listeners, timers, assertions, and configuration elements.
9. What is Work bench?
The Workbench is simply an area to store test elements while you are in the process of constructing a test.
The Workbench is a sandbox for any test or portion of a test that you are working on.
When you are ready to test what you have designed in the Workbench, you can copy or move the elements into the Test Plan.
It also contains Non- Test Elements
Http mirror sever
Http Proxy server
which is not available in the thread group & Test plan
10. Which component, do we need to add, to record script?
We need to add Http proxy server, by simply right clicking on Workbench > Non-Test elements > Http proxy server.
Also need to enable proxy, with port 8080, by going to internet settings> Connections > Lan. Name will be "localhost".
Then click on start button on jmeter http proxy server window.
11. Give a brief history about Jmeter?
A Brief History of Jmeter:
Stefano Mazzocchi is credited for being the developer of this unique tool- Apache JMeter, which is claimed to have been developed to test the strength and performance of the Apache JServ. However; it was later redesigned to make it capable of doing, performance testing, functional testing, regression testing, and unit testing as well.
Since November 2011, the Apache JMeter project has been included in the group of the company’s Top Level projects and today it consists of a separate website and a dedicated Project Management Committee to handle its operations and to provide assistance.
12. Can we perform load testing of database with jmeter?
Yes we can. To see the process follow: Database load testing with jmeter link. You should be aware of sql queries.
13. What are listeners in
Jmeter?
Listeners in jmeter are used to capture the response data of load test. We can have response data (result) in , cvs, image (graph) or in html format.
14. What are the benefits that JMeter offers for performance testing?
JMeter offers benefits on performance testing like,
• It can be used to test performance for both, static resources as well as dynamic resources
• It can handle a maximum number of concurrent users then your website can handle
• It provides the graphical analyses of performance reports
15. How did you go about fixing a performance issue?
Set up JMeter to reproduce the production like scenario to put through concurrent requests and put the system under heavy load. Used a profiling tool to monitor CPU times, memory usage, etc.
16. Name 4-5 listeners in jmeter, which are commonly used.
1. View result tree
2. Summary report
3. Aggregate Graph
4. Response time vs thread
5. Composite graph
17. What is Response time in Jmeter report?
Response time in Jmeter report, is the time taken by web server, to answer the requested query. In simple words, it is the time taken by a web server to respond the http request.
18. What is Spike testing and how can we perform it in JMeter?
Suddenly spiking or increasing the number of users at certain point of application and then monitoring the behavior at that intervals is spike testing.
In JMeter spike testing can be achieved using Synchronizing Timer. Synchronizing timer blocks the threads until a particular number of threads have been blocked, and then release them at once thus creating large instantaneous load.
19. What is median in jmeter listener?
It is a number which divides the samples into two equal halves. Half of the samples are smaller than the median, and half are larger.
20. Explain how JMeter works?
JMeter acts like a group of users sending requests to a target server. It collects response from target server and other statistics which show the performance of the application or server via graphs or tables.
21. What is throughput in jmeter listener?
Throughput is relation between time and data.It shows the relation between http request and unit time. Means how many requests are processed in how much time.
Throughput = Number of requests / Time(second or millisecond)
22. What are the other applications tested by Jmeter?
JMeter may be used to test performance both on static and dynamic resources (files, Servlets, Perl scripts, Java Objects, Data Bases and Queries, FTP Servers and more)
23. Which Jmeter elements are used for Parameterization?
1. User parameter
2. CSV Data Set config
24. Which controllers are used as an conditional controllers in jmeter?
If controller and While controller
25. What are listeners in Jmeter?
Listeners in Jmeter are used to capture the response data of load test. We can have response data (result) in cvs, image (graph) or in html format.
26. What is heap size in jmeter?
Jmeter is work in java, and heap size is related to java. Java heap is the heap size allocated to JVM applications which takes care of the new objects being created. If the objects being created exceed the heap size, it will throw an error of java.lang.out.of.memory.
Java's default heap size limit in Jmeter is 256 MB.
27. What is median in jmeter listener?
It is a number which divides the samples into two equal halves. Half of the samples are smaller than the median, and half are larger.
28. Is it possible that, if we increase the heap size in Jmeter, then application(jmeter) might not work?
Yes, it is possible. Because heap size depends upon the empty space of your machine in c drive as well as your RAM. If the RAM is 1 Gb and you increased the heap 2048, it may not work.
29. Explain parameterization in JMeter?
Parameterization is process of generalizing some user input, so as to use it for multiple users or executions.
30. Which Jmeter elements are used for Parameterization?
• User parameter
• CSV Data Set config
31. Explain what a timer in JMeter is and what are the types of it?
A JMeter thread by default will send requests continuously without any pause. To get a pause between the request, Timers are used. Some of the Timers used are Constant Timer, Gaussian Random Timer, Synchronizing Timer, and Uniform Random Timer and so on.
32. Explain what is the role of Timer in JMeter?
With the help of timer, JMeter can delay the time between each request, which a thread makes. It can solve the overload problem of the server.
33. Explain what is Assertion in JMeter? What are the types of assertion?
Assertion helps to verify that your server under test returns the expected results.
Some commonly used Assertion in JMeter are:
• Response Assertion
• Duration Assertion
• Size Assertion
• XML Assertion
• HTML Assertion
34. What is Blaze Meter?
Blaze Meter is a cloud based service compatible with Apache JMeter. It generates large amount of instant load and provide very comprehensive reporting and analysis features.
In Blaze meter we can just upload the JMeter script and run the load test on cloud with predefined number of users.
35. How do you ensure re-usability in your JMeter scripts?
· Using config elements like "CSV Data Set Config", "User Defined Variables", etc for greater data reuse
· Modularizing shared tasks and invoking them via a "Module Controller".
· Writing your own BeanShell functions, and reusing them.
