JMeter Top most asked Interview Questions | JMeter refresher by Raghav Pal |

00:00 Start
00:39 What is JMeter
01:17 Features of JMeter
02:52 How to setup JMeter on windows & mac os
06:53 Overview of GUI & Features
08:21 How to prepare for a Performance Test
12:51 Test Plan
14:10 Thread Group
16:21 Controllers
16:39 Samplers
18:30 Logical Controllers
19:27 Listeners
23:52 Command Line
26:13 Assertions
28:19 Config Elements
30:04 Timers
32:40 Pre-Processors & Post-Processors
33:37 Test Fragment
34:23 Non-Test Elements
35:36 Execution Order
36:54 Best Practices

#JMeterMostAskedInterviewQuestions

What is JMeter:
Tool or Application for performance testing
Free & Open Source
Built with Java

Features of JMeter:
Completely free
for performance testing of a variety of applications
Web | API | FTP | DB | LDAP
Option for Recording
Inbuilt components for adding assertions & reporting
Extensible using plugins
JMeter is a server-side performance testing tool

How to setup JMeter:
1 - Check java is installed java -version
2 - Download JMeter
3 - Unzip
4 - Start JMeter

Overview of GUI & Features

How to prepare for a Performance Test:
Get approvals & authorizations
Application & Environment
Requirements for the test - What to test, Scenarios
Test Data
Expected behaviour or performance OR Baseline
Reporting Format

Test Plan:
is a like a project where all the elements of the performance test are added
It saves as a .jmx file
Inside JMeter the Test Plan stores & displays the elements of the test in a tree view
A minimal test will consist of the Test Plan, a Thread Group & one or more Samplers

Thread Group:
A Thread Group is a collection of threads
Every JMeter test plan starts with this element
Each thread represents one user using the application under test
In a thread group element, we can define the
No of users (threads)
Ramp up & down
Loops / iterations

Controllers:
JMeter has two types of Controllers - Samplers & Logical Controllers

Samplers:
Tell JMeter to send requests to a server & wait for a response
They are processed in the order they appear in the tree
Each sampler (except Flow Control Action) generates one or more sample results

Logical Controllers:
determine the order in which Samplers are processed
let you customize the logic that JMeter uses to decide when to send requests

Listeners:
Components that show the result of the samplers
Tree | Table | Graphs
also provide means to view, save, read saved test results
Listeners are processed at the end of the scope in which they are found
Listeners can use a lot of memory if there are a lot of samples
To minimize the amount of memory needed, use the Simple Data Writer

Command Line
On cmd prompt
Goto the location of JMeter bin folder
jmeter -n -t “location of imx file” -l “location of result file csv”

Assertions:
Assertion = Check or Validation
Check Actual = Expected
processed after every sampler in the same scope

Config Elements:
to set up defaults & variables for later use by samplers
processed at the start of the scope in which they are found, i.e. before any samplers in the same scope

Timers:
to add delay (pause) before sampler request
By default, JMeter thread executes samplers in sequence without pausing
If more than 1 timers are used in Thread Group, JMeter will take the sum of the timers to pause
can be added as children of samplers or controllers

Pre-Processors:
executes prior to a Sampler Request
modify the settings of a Sample Request Or update variables

Post-Processors:
executes after a Sampler Request
to process the response data, to extract values from it

Test Fragment:
special type of controller used with the Include Controller & Module Controller
not executed unless it is referenced by either a Module Controller or an Include_Controller.
This element is purely for code reuse within Test Plans

Non-Test Elements:
HTTP Mirror Server
HTTP(s) Test Script Recorder
Property Display

Execution order:
Configuration elements
Pre-Processors
Timers
Sampler
Post-Processors (unless SampleResult is null)
Assertions (unless SampleResult is null)
Listeners (unless SampleResult is null)

Best practices
1. Always do performance testing on a separate env - not used for other activities
2. Run your tests with the same infrastructure, network stats etc. - consistent results | compare with baseline
3. Create more realistic test - add think time
4. Add some ramp up, Do not start directly with 1000 users
5. Always have a baseline to compare your test
6. JMeter checks the server performance & does not care for browser render time
7. Focus on the areas that need performance testing based on user scenario
8. Always document your results

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Never Stop Learning
Raghav

[NeverStopLearning]

Do we have any scenario based interview questions?

[ramanareddy]

One of the greatest thing and I like the second most thing from Raghav Pal is adding the notes in the description. The first thing I love the most is his explanation of topics made the learning at ease and less stressful. This is very useful for a reason. Than you Raghav Pal for contributing the knowledge to others. Keep doing the good work sir

[vybhaveswaraiah]

Thank you so much Sir for uploading this, really very helpful. Almost every company asks for Jmeter experience these days when we look for Performance Testing role, please let me know if this content is enough for me to clear the interview as well as to clear the Official Jmeter Intro Certification Exam ??

[vipintekade]

Hi Raghav please make a video for Jmeter performance testing using beanshell interview questions?

[adarshjain]

Hi raghav asking feom interviews perspective and realtim work.. Does one needs to have scripting coding knowledgea for performance testing and that also in jmeter...? Like bash scripting would be required...

[modernlifemanager]

Hello Raghav
I have one question related to Neoload. Can you please help me with a short video.
In Neoload, I am correlating the whole response body and printing it in a javascript through assigning it in a variable. Now, I want to access any of its key pair value but not able to do so. For example if the Response body contains some value let's say "name": "Raghav" and I want to get this name in a variable and want to print in the console using JavaScript in Neoload. Please help.

[sakthivel-hjry]

Hello Raghav sir, could you please upload video for mobile performance testing, I'm not able to record the script for mobile application, i referred your videos eventhough not able to record the script, can you please help us

[vinodcse]

You are simple and cool tutor. Unique Guy. Keep it..

[shotongopro]

Hi raghav, could you please attach a PDF for the interview question

[abdulmuneer]

Can we do performance test in Production environment??

[harish]

Sir can u provide neoload and load runner detailed tutorials plss it would be very helpful to u

[swathypremdas]

Thanks a lot Raghav.. I have a performance testing interview on this Saturday. I have completed your jmeter beginners entire course and this one. Also in my current project I have created simple test plans also.. Is it enough for this interview? Do I need to check on intermediate level videos also?

[nilambhoir]

Very helpful..Appreciate u r hardwork👏

[SineQuaNon]

Thanks Raghav. As always, a very useful video. You are a great teacher.

[aryaabinash]

Hi Raghav Sir, this is helpful and thanks for helping so many with your teaching.
Your channel is so good that I have two subscriptions with different accounts.
I have one question, can you please make a video in which we can know the real customer scenarios for JMeter test with API testing from your experience.
Some real time customer scenarios.
Also how to use the Groovy inside the JMeter and use it.
Thanks

[balajikammili]

brother please do video about data base

[prem]

When we load Url of my project . Microsoft login page appear and has api as ' authorize?client_id' it has a parameter client-request-id from where value is appear . And how to automate through jmeter. Simply asking how to correlate client-request-id

[ayanaroshini]

Hii Raghav ...iam having one issue ...iam working in for one of the MNC ..iam working as performance tester using jmter...my issue is after recording. body(not response body) data is commenting.which ever data is passing in the body entire data is commented. Commucated with development team as well .they said that body of data containing the application URL..cause of forward slash (//) tool is commenting data.
Is there any way to over come this issue . Can u let me know the resolution if having any idea about data commented in body.

Thank you in advance

[urmaddy]

Humble request :-. Try to show demo in windows laptop.

Your most of videos are in Mac OS.
🙏

[sandhyareddy]

Hi Raghav, in loadrunner we have 3 pacing options, and almost we go with -start new iteration at fixed intervals every **** seconds Let's assume me have given 60 sec as pacing and our iteration is taking 58sec then it will wait for 2 sce before starting the nxt iteration and if the iteration is taking 62 sec then the nxt iteration starts immediately without any wait time.... How can we implement this in Jmeter?