Everynow and then, Vugen will have a little episode and decide that its default results directory is locked, and you will be presented with an friendly dialog box like the one below.

If you have ever wondered what is going on, it turns out the culprit is mmdrv.exe. This executable is the Multithreaded Driver Command Line application that is used to simulate virtual users, and killing all instances from the task manager will remove any locks on your results directory, and you can go back to normal vugenning.

While most of us don’t mind using multiple directories, it seems that even in Vugen 11, the replay log window will always show the log of the first results directory after playback. This can be very confusing when debugging scripts.

This exe can also be used manually to execute vuser scripts from the command line. This can be handy for environment smoke tests. I will write more about some alternate uses for mmdrv.exe in a later post.

Here is a familiar situation. Thousands of potential accounts for use in performance testing, some of which work, some don’t. In this example, it’s the login credentials. This usually requires you to run through your test data one by one to see which accounts work, and which don’t, removing the accounts that error. By turning off HTTP redirects, you can speed up this process significantly.

This example script is a minimalist way of checking the data in a fairly quick way, without the burden of actually loading the pages. All you need to know is the URL that you are redirected to on successful login (or failure). In this example, the user is redirected to /dashboard.php on successful login.

// Disable HTTP Redirects to time Authentication
web_set_option("MaxRedirectionDepth", "0", LAST);

// Find Authenticated URL
web_reg_save_param("redirect_url", "LB=Location: ", "RB=\r\n", "Search=Headers", LAST);

web_submit_data("web_submit_data",
	"Action=http://www.headwired.com/login.php",
	"Method=POST",
	"TargetFrame=",
	"Referer=https://www.headwired.com/login.php",
	"Snapshot=t3.inf",
	ITEMDATA,
	"Name=username", "Value={INPUT_USERNAME}", ENDITEM,
	"Name=password", "Value={INPUT_PASSWORD}", ENDITEM,
	LAST);

if(!strcmp(lr_eval_string("{redirect_url}"),"https://www.headwired.com/dashboard.php")) {
	// Login Successful
	lr_output_message(lr_eval_string("Login Successful - {INPUT_USERNAME},{INPUT_PASSWORD}"));
}

Some of you may want to write the valid and invalid accounts to a file, yet for a once off execution, this method suits me just fine.