web_concurrent_start & web_concurrent_end

Need for Concurrent group functions:

A web page contains elements like html, jpeg, png, css service call and so on. When we try to load a web page of this kind, all these different elements make a parallel call to the servers to get loaded up. So at the end it is a single page that loads in front of our eyes.

These parallel concurrent calls can be simulated in Loadrunner using web_concurrent_start & web_concurrent_end functions. All the requests of the elements in a web page are recorded in-between these concurrent group functions. Thus making the simulation more realistic.

We can select this option under Recording Options -- Recording  -- HTML Based Script -- Non HTML - generated elements ( Record in separate steps and use concurrent groups )

What is concurrent execution?

Different multiple requests executed at the same point of time.

Characteristics:

• The web_concurrent_start & web_concurrent_end functions mark the beginning and end of a concurrent group.
• Functions (requests) included within the concurrent group are not executed immediately
• web_concurrent_start registers the functions (requests) for a concurrent execution.
• web_concurrent_end executes all the registered functions concurrently.
• These functions are supported for all Web scripts.