LoadRunner:Verifying LoadRunner data transfer

pcl2004_27

Description

      Tips on how to make sure that LoadRunner is pulling down all the files you think it is


Solution

      A common request from many new users of LoadRunner is for a method by which they can verify that their LoadRunner scripts are pulling down all the data they think is being accessed.

There are three relatively easy ways to do this.

1) Use the VUser logging capabilities of the LoadRunner Controller. The key is to enable the logging of data sent back from the server. This will place the binary data of the object request responses in your logs, so it is not recommended that this be done during large VUser runs, but rather during smaller test runs to verify script functionality.

After the test, open the VUser logs and look for the filenames you wish to verify. If you see the response from the server with the desired filename (and the accompanying binary data for that file), then LoadRunner successfully transferred that data during the course of the test.

2) Use a software packet sniffer. Using a sniffer, you can monitor all the traffic between a workstation and a server. What you want to look for are the GET requests made by LoadRunner and the resulting responses from the server.

I find it easiest to use a sniffer while doing a VUser test run from localhost.

I recommend using Ethereal for most basic sniffing tasks. It's available at www.ethereal.com.

3) Enable logging on the web server. By enabling logging for all files transferred, you can easily see which files have been requested/sent and how many times this happened. You can also use server usage statistics programs like Webtrends to cull this data and present it in an easily accessible format.

With those three methods, you should be able to see everything that happens between LoadRunner and your web server. Doing this kind of verification can be time intensive, but it is better to know that you are simulating accurate load than to later find out that all your tests were invalid because key data files were not being retrieved.