From: Prasant 
Sent: Monday, August 04, 2008 7:55 AM
To: Tomlinson, Mark
Subject: Some questions about LR 

Hi Mark,

I am Prasant . I got your mail id from yahoo LR group. I have just started my career in Performance testing. I got a chance to work on LR . Currently I am working with LR 8.1. I have one doubt regarding think time. While recoding one script automatically think time got recorded in the script. While executing the script I am ignoring the think time. Is it required to ignore the think time or we have to consider the think time while executing the script.

I have questions in mind like, when think time is considerd as [time] the user is taking before giving input to the server . In that case while recording any script for a particular transaction I may take 50 seconds as think time and my friend who is recording the same script will take less than 50 seconds (let's say 20 seconds). So, in his script and in my script the think time will vary for same transaction. If I will execute both the scripts considering the think time the transaction response time will vary . It may create confusion for the result analysis. Can you please give some of your view points about this.

Thanks,

Prasant

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From: Tomlinson, Mark 
Sent: Thursday, August 07, 2008 2:59 AM
To: Prasant
Subject: RE: Some questions about LR 

Hi Prasant,

Yes – it is good that think time gets recorded, so the script will be able to replay exactly like the real application – with delays for when you are messing around in the UI. But you must be careful, if you are recording your script and you get interrupted…or perhaps you go to the bathroom, or take a phone call…you will see VERY LONG THINK TIMES getting recorded. You should keep track of this, and then manually go edit those long delays – make them shorter in the script. Make them more realistic, like a real end user.

Also, as a general rule of thumb you should try *not* to include think time statements in between your start and end transactions. You are right that it will skew the response time measurements. But for longer business processes where you have a wrapper transaction around many statements…it might be impossible to clean every transaction.

Here are 3 other tips for you:

First – in the run time settings, you have options to limit or adjust the think time settings for replay…you can set a maximum limit, or multiply the amount. The combinations are very flexible. You can also choose to ignore think times and run a stress test, although I typically will include even 1 second iteration pacing for most stress tests I run.

Second – you can write some advanced functions in the script to randomize the think times programmatically. This could be used to dynamically adjust the think time from a parameter value, in the middle of the test.

Third – even if you do have think times inside your start and end transactions, there is an option in the Analysis tool to include or exclude the think time overhead in the measurements displayed in the Analysis graphs and summary.

I hope you’ll find that with those 3 tips, you can get all the flexibility you need to adjust think times in your scripts – try to make the most realistic load scenario you can.

Best wishes,

Mark