JMeter, also known as Apache JMeter, is an open-source performance testing tool developed by the Apache Software Foundation.
It is mainly used for load testing and performance testing of web applications, but it can also be used for functional testing and other types of testing.
JMeter allows testers to copy various user scenarios and measure how web applications perform and respond under different loads. It can generate a large number of virtual users at the same time, sending requests to the application and collecting data throughout on response times, error rates, and other performance measurements.
Some key features of JMeter include:
1. Test Plan Creation: Testers can create test plans using JMeter's graphic user interface (GUI) or by writing test scripts in its scripting language. Test plans define the scenarios, user actions, and requests to be copied during the performance testing.
2. Test Configuration: JMeter offers wide program options to copy realistic user behaviour, including setting up HTTP requests, managing cookies, handling data which is sent forward, and programming headings and limits.
3. Load Generation: JMeter allows for the creation of realistic load scenarios by copying a large number of users at the same time, each performing a specific set of actions on the web application.
4. Result Analysis and Reporting: JMeter generates detailed test results and performance reports in different forms, including graphs and tables. Testers can analyze these results to identify areas where performance is slow, identify errors, and assess the application's performance under different loads.
5. Can be extended: JMeter can be extended very easily and supports plugins and custom scripts, allowing testers to improve the way it functions and connect it with other tools and systems.
JMeter is widely used in the software testing community for performance, stress, and load testing of web applications. It offers a flexible system that can easily be adapted for measuring and analyzing application performance, helping to identify and solve performance-related issues before starting to use applications in production environments.