LoadRunner Tips and Tricks

From http://blog.testsautomation.com/2010/07/my-loadrunner-tips-and-tricks/

Few tips&tricks to make working with LoadRunner easy:

- Store URL of your application in one single parameter. In case you need to change it, it requires a single change in one place, not tons of them for every single web request.

- If you don’t know why your HTTP/HTTPS request is failing, use proxy to sniff it and them compare it with the same request but generated from real browser. As a proxy you can use WebScarab or Fiddler.

- Separate load logic using actions, don’t store whole load in a huge single action that LR created be default at the beginning.

- Create web_reg_find() checkpoint for every HTTP request that you make. You don’t want to pass failing transations.

- On parameter setup, beware using “Update value” set to “Once”. Rather use “Every iteration”. If you mess it up somehow, at least only current iteration will fail, not all of them.

- For scripts that handle UI actions (like Web Click&Script or AJAX Click&Script) use “Run every user as a process” instead of “Run every user as a thread”. LR is not very good at memory management for such scripts so it’s better to run each vuser separately.

- Don’t use extended log level while running test in a Controller. One more time LR is not very good at handling it. Rather use basic level and if there is an issue switch to VuGen to digg for it.

- In LR Analysis, check performance results on a summary graph instead of “Average transactions response times” graph.

- Place 1 second wait before first call to the server. If server breaks, you won’t flood it with bunch of requests.

- Try to avoid using standard C string functions (strcpy, strcat, etc…) if you can. Or if you really need, just remember about null pointer issue. More details here http://blog.testsautomation.com/2009/11/exception-access_violation/.

- Comment your code – at the end LR script is (most cases) a C program. So all programming best practices apply as well.

- Make your code to look nice (tabs, indents, etc…). It will be easier for you to work with it and spot any issue.

- Don’t hard code anything. Instead put it into parameter.

- If some calls repeat constantly, put them into separate action and call this action instead. It will help you during refactoring your tests.

- NEVER store Controller scenario in QualityCenter. It’s just bad idea. Use local hard drive for it. Controller can store really big files there.

- When you work on a script in VuGen, try to run it there at lest for 2 or 3 iterations. Sometimes errors occur only after the first iteration.

- If you want you can store LR script on a shared drive. It won’t affect your tests since Controller will always copy it to temp directory before running the scenario (even if the script is stored locally on the same drive).

- If you want to send LR script to someone use File -> Zip Operations -> Zip and Email. On popup select “Run-Time files” instead of “All files”. This second options can zip results as well which may generate really unnecessary huge file.