A Detailed Overview of Pre-Processors and Controllers in JMeter (Part III):
=> Explore our broad array of free JMeter tutorial content here
Recommended IPTV Service Providers
- IPTVGREAT – Rating 4.8/5 ( 600+ Reviews )
- IPTVRESALE – Rating 5/5 ( 200+ Reviews )
- IPTVGANG – Rating 4.7/5 ( 1200+ Reviews )
- IPTVUNLOCK – Rating 5/5 ( 65 Reviews )
- IPTVFOLLOW -Rating 5/5 ( 48 Reviews )
- IPTVTOPS – Rating 5/5 ( 43 Reviews )
This piece will offer users a detailed, step-by-step guide on using Pre-Processors, Post-Processors and Controllers in JMeter. Controllers play an integral part in creating credible testing scenarios.
Frequently, testers have to examine various scenarios where they can tailor the sequence of requests sent to a server to track response time and other performance indicators.
Table of Contents:
Pre-Processors
Pre-Processors run before a sampler is carried out. A Pre-Processor can be linked to a sampler to modify the request.
Taking an example, one could add an “Sample Timeout” Pre-Processor to a HTTP Request to limit its execution duration. This adjustment is only applied to the parent sampler.
The following is a list of frequently used Pre-Processors in JMeter:
- Bean Shell Pre-Processor
- HTML Link Parser
- HTTP URL Re-Writing
- JDBC Preprocessor
- Sample Timeout
- User Parameters
In future sections, we will discuss the most widely used Pre-Processors in conjunction with examples. You may not need all of these for your projects. Identify your project-specific scenarios and then apply the Pre-Processors that fulfill real-time performance requirements.
User Parameters
User Parameters are utilized to assign values for variables before they are used in samplers. When the JMeter executes this Pre-Processor, it stores the values in variables that can be referenced by any samplers inside the same thread group.
If your number of threads exceeds the number of users specified in “User Parameters”, the additional threads will cycle through the values again.
To illustrate, if your thread group comprises five users but only three in the Pre-Processor, param1 and param2 will be utilized by the fourth and fifth threads.
Sample Time Out
The Sample Time Out Pre-Processor is employed to specify the timeout period for requests.
For instance, if you stipulate a sample time out of 400 milliseconds, any requests that take longer than 400 milliseconds will return a failed response. Refer to the screenshots below for more details.
Controllers
Controllers are instrumental in forming authentic JMeter test plans. They dictate the sequence in which requests are delivered to the server.
As an example, should you wish to examine a web application where a login should occur once and requests for search/item selection need to be sent one after another for every iteration, controllers can make this feasible by controlling the succession of requests to the server being tested.
The most frequently used controllers in JMeter are listed below:
- Simple Controller
- Module Controller
- Once Only Controller
- Interleave Controller
- Loop Controller
- If Controller
- For Each Controller
- Recording Controller, etc.
Simple Controller
The Simple Controller lacks any specific functionality. It merely serves as a container used to organize similar requests, thereby making the test plan easier to understand.
Loop Controller
If you need a particular request to perform more iterations than specified in the Thread Group, you can apply a Loop Controller and set your loop count in the controller configurations.
Example: Should you have a thread group with 1 single user and 3 iterations, this results in all requests under this group performing 3 times. However, if there are two HTTP Samplers under a Loop Controller with a loop count of 2, both samplers will run six times (132 = 6).
For further elucidation, please see the screenshots below:
<img class=”alignnone size-full wp-image-15507″ src=”https://iptvassist.com/wp-content/uploads/2021/12/LoopContoller1.jpg” alt=’Loop Controller’ width=”392″ height=”271″ srcset=”https://iptvassist.com/wp-content/uploads/2021/12/LoopContoller1.jpg 392w, https://iptvassist.com/wp-content/uploads/2021/12/1_LoopContoller1-