SoakIE ? a Web Server Stress Tool with a twist

Last week or so ago a couple of friends in another project in Cognifide has run into a wall while trying to load test their website. the problem was as follows: The website is highly AJAX based ? the page merely loads a stub in the initial request but then loads the rest of its data in a dynamic matter therefore a traditional web testing tools are fairly useless. What they tried was to setup a number of Selenium clients to pound the server, but that turned out to be fairly challenging to the machine doing the testing. It was not possible to set up more than 10 clients on a fairly strong machine.

Also there are other limitations like time to wait for the server to timeout and time between clicks, which I am not sure the tool allowed them to adjust. Talking to them I recalled a tool for grabbing website thumbnails long time ago. one way for them would be to to make a batch file with it. The tool would grab the sites? thumbnail and stress it, but they would still have to setup a number of clients. Also it creates and tears down an instance of IE every time, making it?s not optimal for that task.

So a couple of evenings later (and a few back-s and forth-s during the testing sessions) out comes SoakIE:

The app uses pretty much the same trick as the tool for grabbing website thumbnails but it does so in a nice UI and allows for some rudimentary settings for profiling the traffic:

You can select the number of IE instances that will do the clicking, you can select a minimum time between clicks ? that is how often any IE instance can click (if it already finished with the previous request). this allows you to simulate clients that will stay a minute on your site and only click after they?ve read the page. Additionally if your application can on an occasion encounter a deadlock or a hang, it allows you to specify the maximum time to live of each request. If the request takes longer than the specified time, the application will ?Stop? the request.

One thing that we?ve noticed though is that after a long time of soak tests the IE instances get mighty fat and start to slow down dramatically. Therefore I?ve added a maximum number of clicks an IE instance can perform after which the client will no longer recycle it for more click but will tear it down and create a new IE instance to continue testing.

Naturally the application needs to know what to test. This is specified in the ?Test setup" tab in the ?URLs to stress:" text box. The URLs will be picked in a round-robin fashion. The first browser will get the first url, the next one will get the second and so on, if the list will get exhausted the browsers will get fed it from beginning. You can theoretically put them in the box with some other text (like pasting it from a Skype window without stripping the message decoration around them) ? SoakIE should be smart enough to parse the text and get the URLs out of it.

You can download SoakIE here