Saturday, 17 March 2012

Loadrunner correlation

Correlation overview:
  • Correlation is the way handling dynamic values in client server communication.
  • The values captured will be send back to server in later steps in the script.
  • Correlation is typically used for handling session id's
Correlation Techniques:

Manual correlation
Automatic correlation.

Pictorial view of how correlation works:

  • Below is the snapshot of recording and replaying with out applying:

  • Below is the snapshot of recording and replaying after implementing correlation.

Steps for Manual correlation :

  1. Record two identical scripts with the same business process
  2. Compare the scripts to identify the dynamic value
  3. Search for the dynamic values in the Generation log and Copy Left boundary (LB) and Right boundary (RB)
  4. Replay the script with extended log and look for those boundaries in replay log
  5. Double click in the replay log where boundaries are found and it will take the cursor to the point where dynamic value is generating in the recorded script.
  6. Insert web_reg_save_param("Param name", "LB=" , "RB=", LAST) ; where the cursor is pointing
  7. Replace the dynamic values with Param name