Uh-Oh. This isn't good.

I found out something today that I really don't like with VS2008 for load testing. I created my virtual user and setup think time ala WebTestRequest.ThinkTime with reasonable think times. After the testing was done I moved the results over to my LoadTestHistory database with a SP that I wrote about earlier in my blog. When I examined the results it turned out that the think time was included in the transaction response time. Nope, I don't like that. I dislike that about as much as I don't like having a failed counter for transactions.

I guess I can't be really surprised as the Begin/End transaction is wrapped around the WebTestRequest object and the think time is handled by the WebTestRequest object and there is no communication between the transaction begin/end and the WTR object (AFAIK).

I looked in the schema for the Load Test Repository and didn't see any fields where response time alone (without think time) would be recorded but there is definitely response time without sleep time recorded during the execution of the VS2008 loadtest. I figured there would be a field in the database with this value but I didn't see it.

Luckily, though, this is pretty simple to get around. If you aren't going to be using variable think times you can simple perform a Thread.Sleep(new TimeSpan(0, 0, 0, 5, 0)) which is similar to the LoadRunner idea behind lr_think_time(). Don't forget to add the "using System.Threading;" to your code to reference the Thread object since it is not referenced by default.

If you want to use variable think time then you'll have to come up with your own mechanism for varying the randomness of the think time. It's not that difficult, it is just a pain.