Pacing calculation

[Rao Gadde]

is there any Specific Formula for Calculating Pacing based on TPS or Vusers??

[John Crunk]

Yes

Sent from my iPhone

On Mar 5, 2011, at 1:25 PM, Rao Gadde <gadd...@gmail.com> wrote:

is there any Specific Formula for Calculating Pacing based on TPS or Vusers??

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[Rao Gadde]

what is the formula????

[James Pulley]

Time between beginning of one iteration to the next =

[ Universal_constant  * #Seconds_in_your_sample_window/ (# Samples_in_your_sample_window(Requirements)/#Users_for_your_business_Process(Requirements) ) * (.8|1.2)  /  Universal_Constant  ]

[Gaurav Mishra]

i have a doubt on this part.your pacing formula is absolutely correct but don't you think that due to this it is possible that our system will be idle for a long time. I mean it may be possible that transaction get complete before end of pacing time. so that much time system would be idle. can't we do something to reduce this time. i mean put some variables at time of scripting. which would check running time of script.put pacing as 0. now when ever sufficient time have spent and script is done, next would start on it's own. am i right?

[James Pulley]

Pacing = 0 generally indicates an absence of a load model and a failure in the requirements phase of the project.   The client server model dictates that not all users will be active at any given time and that in the inter-request interval from client A that other clients requests may be serviced.     An individual user being idle due to think time of pacing does not mean that the backend system is idle, for in this interval other requests are being serviced for other virtual users.

 

James Pulley, http://www.loadrunnerbythehour.com/PricingMatrix

 

From: lr-loa...@googlegroups.com [mailto:lr-loa...@googlegroups.com] On Behalf Of Gaurav Mishra
Sent: Sunday, March 06, 2011 10:14 AM
To: lr-loa...@googlegroups.com
Subject: Re: Pacing calculation

 

i have a doubt on this part.your pacing formula is absolutely correct but don't you think that due to this it is possible that our system will be idle for a long time. I mean it may be possible that transaction get complete before end of pacing time. so that much time system would be idle. can't we do something to reduce this time. i mean put some variables at time of scripting. which would check running time of script.put pacing as 0. now when ever sufficient time have spent and script is done, next would start on it's own. am i right?

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[Rao Gadde]

Can you keep the formula in a clear way to calculate pacing..

[John Crunk]

They just did

Sent from my iPhone

[Surendra Ramanapudi]

The below method of pacing is good but there are multiple ways

Usually your goal in load test is to achieve targetted transaction volume right?
Then, first see how long your script takes to execute with out think time or pacing
Then ask the avg visit length of the user for that flowfrom you sme
Adjust the think time or pacing to match the script duration with the visit length
Then next calculate conncurent users
With the think time and pacing + theconcurent users,  you should reach the target transaction volume

Or
I saw one of my colleque never use thank time or pacing
That method is also correct to reproduce consistant tests with cost effectiveness. But that will not be realistic test.

With realistic test it is difficult to produce the defect at the same time because we use ramdomizations for ft and pacing

I hope this helps

[Pavan.Bandaru]

Is there any such formula ever existed???

[James Pulley]

This is not rocket science: If you can't figure this out and you're in the
performance testing profession, well, should you really consider the value
of the training you received?

Load Modeling is a basic skill, like learning double entry accounting. If
your trainer/mentor isn't covering this subject as a part of your
training/professional development then find another one.

James Pulley, http://www.loadrunnerbythehour.com/PricingMatrix

[chaitanya bhatt]

Declaration:

D = Duration of the test(test window/time frame)

 

B = Baseline time(total time taken by 1 Vu to complete 1 whole iteration)

T = Total amount of Think time in the script

I = Expected/Target iteration

R = Residual time of the test window.

R = ( D - (T + B)*I)
 
P = Pacing interval

Dividing the residual time by target iteration gives pacing interval

Hence:
P = R/I

-Chaitanya M Bhatt

http://www.performancecompetence.com

On Sat, Mar 5, 2011 at 10:25 AM, Rao Gadde <gadd...@gmail.com> wrote:

is there any Specific Formula for Calculating Pacing based on TPS or Vusers??

--

[Rao Gadde]

CHAITANAYA

 

what this means   : I = Expected/Target iteration...

[James Pulley]

“what this means   : I = Expected/Target iteration...”

 

This means that it is time to go back to school on performance requirements. 

 

Related disciplines which will provide value here are:

·         Budgeting.

·         Sales Projections

·         Database analysis on the growth of data in the system : what types and how fast?

·         WAN use growth

·         Web server log analysis.  How often is each page hit?  Can a growth curve be projected?

·         Systems engineering related to the sizing of hardware

 

James Pulley, http://www.loadrunnerbythehour.com/PricingMatrix

 

 

 

 

From: lr-loa...@googlegroups.com [mailto:lr-loa...@googlegroups.com] On Behalf Of Rao Gadde
Sent: Monday, March 07, 2011 11:14 PM
To: lr-loa...@googlegroups.com
Subject: Re: Pacing calculation

 

CHAITANAYA

[prasenjit dutta]

excellent  chaitanya.....really appreciate u to make this so simple......

--
Prasenjit

[Rao Gadde]

what this term implies : Residual time of the test window means???