What are Listeners in JMeter?
JMeter Listeners are the test plan elements that are used to view and analyze the result of performance tests in tabular or graphical form. They also provide the different response time matrices (average time, minimum time, max time, etc) of a Sampler request. How to add a Listener-
Right Click on Test plan -> Hover over Add -> Hover Over Listener -> Click on the required Listener
We can add listeners as child of a particular Thread Group also. In that case, the Listener will use the data of that Thread Group for analysis.
*Please note that it is good practice to store the Test results in a .jtl files. This file can then later be loaded into a Listener to create graphs and perform different functions provided by different Listeners.
Different Listeners Provided by JMeter
The Aggregate Graph listener is used to display the test results in both tabular form(reports) and graphs.
The Aggregate Report listener is used to display and store test results in the form of reports.
The assertion results listener is used to display the assertion result for each erroneous sampler response. It is advised to not use this listener during the performance test as it is very resource-intensive. It should be used while debugging and functional testing only.
The backend listener is a special type of asynchronous listener used specifically with BackendListenerClient for its customization.
The BeanShell listener is used to enable BeanShell scripting in JMeter. For details on BeanShell Scripting check our tutorial Bean Shell Scripting in JMeter.
The BeanShell listener is used to enable BSF scripting in JMeter.
Comparison Assertion Visualizer
The Comparison Assertion Visualizer is used to provide a comparison between assertion result in an easy to compare UI.
Generate Summary Results
The Generate Summary results listener is used to store and display detailed test results to log files.
The Graph results listener is used to display each sampler request’s response time graph in terms of average, median, deviation, and throughput.
The JSR223 Listener is used to enable JSR223 scripting in JMeter.
The Mailer Visualizer sampler is used to provide the functionality of sending customized mails in case of some specific error threshold.
This is a newly added listener in JMeter used to display and store server performance stats.
Response Time Graph
The response time graph is used to provide the graphical representation of response time with time elapsed during the test run.
Save Response to a file
The save response to a file listener is used to store the sampler response in a file. This listener is used while functional testing or debugging the test script.
Simple Data Writer
The simple data writer listener is used to save the sampler response to a file after with different configurations to remove several unnecessary overheads.
The summary report is used to store and display the test result in tabular form just like an aggregate report listener but consumes less memory(as per Apache JMeter).
View Results Tree
This listener is used to provide and store test results for each and every individual sampler.
View Results in Table
The view results in a table listener are used to display the sampler response header and response body.
That’s all we have in this post, please share it with your friends and colleagues. Check out the complete JMeter tutorial here.
Apache JMeter User Manual