Load Testing of web application using Jmeter

Jmeter is open source tool from apache to test performance of application when large number of users access in small amount of time .

This not a browser but it is software which simulated request and response condition which happens at actual time.
Jmeter does not execute your Java scripts , render ajax request etc .It just creates http request object in case of web application and set proper parameter in it.So if you want to analys time taken by each page loading then it would be time difference between request and reposes .Actual browser will take some more time depending on type of browser and its caching mechanisms .
In practice it is very impossible to create scenario in which 1000 users logs in to system and try to play with it .Jmeter virtually creates given numbers of threads which can innudate the server with hhtp request .

Stress testing / Load testing is concept from mechanical engineering in which we test how much requests server can handle without going out of memory :)
Jmeter has pretty long learning curve .


From scratch if you have to do something minimum one week will require to just create a demo .
Lot of problems come in this like cookie manager policy , URL rewriting , creating login and password mapping for say 100 users .


To use you much know main terminologies in it .

Main terminologies

Element	Description
Thread Group	As with any load test, execution is multi-threaded. The thread group element is what controls concurrent connection to your application. In end user terms, it's your group of users.
Samplers	A sampler is the basic type of controller. Very simply, samplers tell JMeter to send requests (HTTP, SOAP, etc…) to a server. There are also Logic Controllers, but we won't be using one in this tip.
Listeners	Listeners are what you use to access to the information JMeter gathers while running. They give you the pretty charts
Timers	Timers are how you set delays in JMeter. Timers fire before each request that a thread makes.
Assertions	Assertions, like in any test tool, allow you to check for specific behavior as your test executes. Assertions provide the standard pass/fail results.

Installation –

Ø Please refer to installation video - Installation video

· Download from

http://jakarta.apache.org/jmeter/

· Download zip file - Unzip it at c: / drive

Ø Please refer video to learn how to use it - You tube video is planned .

Steps to follow -

Scenario -

I am taking general scenario in which you have to log in to system and hit some pages .
Lets consider that 100 users hit the same page in period of one second .

First you have to record all requests and responses using Jmeter then run for 100 users .

Please refer to you tube video lecture for this

How to use Jmeter.

References

1.Jmeter reference book

http://www.doc88.com/p-7040136164.html

2. Apache user manual

http://jakarta.apache.org/jmeter/usermanual/index.html