This feature allows the settings of a concurrent connection pool for retrieving embedded resources as part of the HTTP sampler.
Why is this feature so important?
How does a browser do it?
Once a browser fetches a page, it subsequently fetches all of the page’s embedded resources (i.e. images, style sheets, script files, etc.). During fetch time, the browser can open a series of parallel connections to the remote server(s) hosting the embedded resources. Fetching the content of a page using parallel connections dramatically reduces the render time.
Note just how many embedded resources were fetched in parallel.
The concurrent connections feature allows JMeter to create a more realistic simulation. By allocating a pool of threads to retrieve the embedded resources, JMeter’s behavior more closely emulate the behavior of a browser. The response time is shortened and more inline with the render time of a browser. The load is more realistic and much higher.
When comparing test results when running the same test with the connections pool enabled with 4 threads and when not enabled, it is obvious that the average response time without the connections pool was: 13,644 ms and with the connections pool enabled it was 5,557 ms.
Of course activating the concurrent connections pool has an affect on resources consumed by JMeter.
Want to learn more? You'll want to view our on-demand recording, How to Create Advanced Load Testing Scenarios with JMeter