In this blog I will show a way to do performance testing with Selenium. The reason I use Selenium for performance testing is that some applications use proprietary protocols between the application layer in the browser and the server.
So just capturing the traffic between the server and replaying modified traffic is not that simple.
An example is testing GWT applications. In a previous blog I wrote why this is difficult.
To create a test script in Selenium the first thing I do is record a test with Selenium IDE
After recording a script I export the script to JUnit3 (Remote Control). This will generate a JUnit test script which can be run to test the application.
The next thing you need is a solution to run a lot of JUnit test cases at the same moment.
Here you see a visual representation of the whole test chain.
common in the java coding world. It is, however, applied to the unit-test level only: one writes a unit test that shows a particular feature is not (properly) implemented yet. The test result is “red”. Then one writes the code that “fixes” the test, so now the test succeeds and shows “green”. Finally, one looks at the code and “refactors” the code to ensure aspects like maintainability and readability are met. This software development approach is known as “test driven development” and is sometimes also referred to as “red-green-refactor”. 
