Load testing- JMeter Part 1

Load testing focuses on simulating and often exceeding your expected production load, throwing many concurrent requests at your site for an extended period of time. The key to load testing is realism. You need to know your application and your audience well, so that you can balance your load across your application in a way that closely mimics your actual or expected production traffic.  

While your load test is executing, you have the opportunity to monitor your entire server stack and see what happens over time as your application handles the load. As time progresses, the load should shift. This could be because more pages are being cached, or more keys are being invalidated. Your application servers may be waiting on external services, or you could see swapping increase as your servers run out of physical memory. Load tests give you the opportunity to see how your site will perform when the going gets tough. 
There are many tools available from many vendors for load testing this includes win runner, load runner, JMeter and some use batch scripts. There are many other tools as well. A list of such tools is available at following link for wikipedia
http://en.wikipedia.org/wiki/Load_testing#Load_testing_tools

Here we will discuss about JMeter.

JMeter is a Java based tool for performing load testing client/server application. The important functionality of JMeter is a heavy load on the server can be simulated by using it and not just on server but also a heavy load on a network or an object can be tested for its strength under different load test. A graphical analysis of performance can also be obtained by using JMeter or the behavior of the script.

Jmeter Installation:

The latest version of JMeter is 2.8 which you can download from the below mentioned URL:

http://mirrors.ibiblio.org/apache//jmeter/binaries/apache-jmeter-2.8.zip

once you download the JMeter zip file you need to unzip it. JMeter is compatible with JDK 1.5 environment and it can be downloaded as .gz or .zip files. To run JMeter you need to extract the binary distribution file. JMeter can be run on different OS as described below:

• You need to invoke the JMeter shell script on Linux/UNIX to run JMeter.
• If you want to run JMeter on WINDOWS then call JMeter.bat file. You can find both the files in the bin/ directory of the JMeter installation directory.

The JMeter's main window is displayed below which is a Swing application.

Apache-JMeter

  A simple test using JMeter will be elaborated in upcoming posts