srigowri

• Mar 10th, 2006

 

While recording the server when receives any request from the client , sends an unique id for that session. When client again communicates with the server , server recognizes this session with this session id. But while replaying this vugen script , the server sends another session id , but the client communicates with the server with the hardcoded session id(got while recording), which server cannot recognize , so it fails.  So Correlation studio in the web based protocol will correlate the new unique ids. But becoz not always is the correlation studio is perfect. So we must go with the manual correlation.

spsripal

 Profile Answers by spsripal 

• Mar 13th, 2006

 

Correlation is the Process by which we can capture and Resubmit the Dynamic Values During the Script run in Virtual User generator to Avoid Standard Session Id's.

Session Id's are Always Changing by the WebServer. So when you Run the Script in Controller the Session Id 'll be captured by the Correlation Script. To do so We use web_reg_find function.

mohangopi

 Profile Answers by mohangopi 

• Apr 20th, 2006

 

Hi!

  Correlation is one of the utilities of Loadrunner, used for uninterrupted execution of scripts running 'n' no of times [ parameterization ].

Let me explain a scenario :

  We  parameterize a script to run for 5 times [ 5 iterations ] .

There may be some dynamic values ( or unique values ) which will be created by the application or the server when it runs the script on first iteration.  

Now when the second iteration comes, Load runner expects the same dynamic value for the second time.

Here comes the concept of using Correlation.

So, correlation instructs Loadrunner to ignore the new dynamic value getting created at each iterations.

 

vinsingh_2002

 Profile Answers by vinsingh_2002 

• May 3rd, 2006

 

You are definitely correct Gopinath . Standing ovation for you. Clap Clap Clap.

CHARAN

• Aug 25th, 2006

 

Process of capturing dynamic values returned from server using WEB_REG_SAVE_PARAM function..

Romi

• Nov 13th, 2006

 

hi,

I1ve read your answer but I would like to know : why we want the LR to use the same dynamic value it used in 1 iterations?

thank you

koteshst

 Profile Answers by koteshst 

• May 6th, 2008

 

Dynamic values important because, everytime a web request goes to server comes back, certain values in the session are changed by the server dynamically. If we have used correlation for those values, that will take care of them automatically.