JMeter is used for the performance testing of web applications. You can easily calculate per second load on any web application by using JMeter. However, collecting and interpreting the results of JMeter analysis can be a confusing task as there are a number of ways to do this.
In this blog, we are going to discuss the JMeter Listeners, response time, and hits per second.
Types of Listeners
Performance Testing data can be seen in the form of different Listeners. To use listeners, we create a test plan and a thread group. Then, we define the number of users and their loop count in this thread group.
After that we add listeners in the Thread Group and the listener shows the result in different formats.
Three important listeners are listed below –
The Graph Result describes the application performance in graphical form. It displays per minute load which is called throughput and also depicts the number of samples used for evaluating performance. It also represents the median and average values.
View Result in Table
Result Table is the second type of Listener and shows output in seconds. It shows per second load. The Thread Name, Start Time, Sample, Status, Bytes, and Sent Bytes are also shown in the Table. This data is beneficial in case the graph result is not much understandable.
View Results in Tree
Another listener is Tree form. It shows Request, Request headers, Response, Response headers & error and basically used for API evaluation. If some error appears then it indicates it in red color. If response receives successfully then sample is shown in green color.
We can save JMeter Data Results in the form of JMX files. To generate reports in JMeter, you have to hit the below-given command-
JMeter -n -t jmx file -l log file -e -o output folder path
-t => It is used to define test jmx file
-l => It is used to define log files
-o=>It is used to define output folder path
When we execute the above command, the result logs are shown in the below screenshot –
We can also Generate Html Report using Tools >> “Generate Html Report” option-
Parameters details are given below-
|Results file (csv or jtl)||Output of test||Yes|
|user.properties file||File is used to run the load test||Yes|
|Output Directory||Report Output Location||No|
Response Time Vs Request
The above graph shows the result in the form of Response Time & Request per second. Requests per second depending upon the number of samples. It also includes loop count, which means a request can hit the application server multiple times.
Hits Per seconds
Above graph shows the number of samples per second or we can say in a second how many requests hit to the application server.
We can also generate sample CSV load file using this command-
JMeter -g log file name -o path to output folder
How JMeter simulates the heavy load, it can be explained in the image below-
In the above graph, it is explained that different threads are hitting the application in the same duration of time. It depends on how much load an application can bear. A user can hit an application multiple times, it depends on loop count. Total samples are defined by multiplication of the number of users and loop count. If 100 users & 10 loop count exist then total samples will be 1000.
Some important factors that are required in the result analysis of performance testing are-
=> The throughput is the most important parameter. It represents the ability of server to handle heavy load. The higher the throughput, the better the server performance.
=> The deviation is indicated in red – it indicates the deviation from average.
JMeter Test Result Analysis
At the bottom of the image, you can see the following lines-
- Black: The total number of current samples sent.
- Blue: The average of all currently sent samples.
- Red: The current Standard Deviation.
- Green: Throughput rate that represents the number of requests per minute the server handling.
The listeners play a very important role in performance testing, but it should be noted that it should not be used while load testing.
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