Mastering Performance Testing with JMeter

Summary:

In software development, ensuring optimal performance of the application is the most crucial factor. Performance testing plays a crucial role in evaluating the responsiveness, scalability, and stability of software applications under various load conditions. Among the diverse variety of performance testing tools available, Apache JMeter stands out for its robust features, flexibility, and open-source nature. In this article, we will dive into the various aspects of performance testing using JMeter, exploring its usage, key features, step-by-step execution, dependencies, analysis/reporting capabilities, and add-ons.

Usage:

• Apache JMeter is a Java-based open-source tool.
• It is primarily used for load testing, performance testing, and stress testing of web applications, FTP servers, databases, and more.
• JMeter allows testers to simulate heavy loads on a server, network, or object to analyze performance under different conditions.
• It supports various protocols including HTTP, HTTPS, FTP, JDBC, SOAP, LDAP, JMS, SMTP, and more.
• This versatility makes it suitable for testing a wide range of applications.

Key Features:

• User-friendly GUI: JMeter provides an intuitive graphical user interface (GUI) that facilitates easy test script creation, configuration, and execution.
• Distributed Testing: With JMeter's distributed testing capabilities, you can distribute the load across multiple machines, enabling scalable testing scenarios.
• Support for Multiple Protocols: JMeter supports a wide range of protocols, allowing testers to simulate real-world scenarios and interactions.
• Rich Test Plan: Test plans in JMeter are highly configurable, allowing testers to define scenarios, add listeners for result analysis, and set up assertions for validating responses.
• Scripting Support: While JMeter offers a GUI for test creation, it also supports scripting for advanced users who prefer code-based test scenarios.
• Extensive Reporting: JMeter provides comprehensive reporting capabilities, including graphs, tables, and result analysis tools, to help identify performance bottlenecks and areas for improvements.

Dependencies:

JMeter requires Java Development Kit (JDK) to be installed on the system as it is a Java-based application. Additionally, it may have dependencies on external libraries or plugins depending on the specific testing requirements.

Step by Step Execution:

1. Test Plan Creation: Start by creating a new test plan in JMeter

2. Thread Group Configuration: Add a thread group to the test plan and configure parameters such as the number of threads, ramp-up period, and loop count.

3. Sampler Configuration: Add samplers under the thread group to simulate user actions such as HTTP requests, FTP requests, JDBC requests, etc.

4. Assertion Configuration: Define assertions to validate the responses received from the server.

5. Listeners Configuration: Add listeners to collect and analyze test results. JMeter provides various listeners such as Summary Report, View Results Tree, Aggregate Report, etc.

6. Execution: Execute the test plan to simulate the desired load on the target application.

7. Result Analysis: Analyze the test results using the built-in listeners and reporting tools to identify performance issues and bottlenecks.

Reporting and Analysis:

JMeter offers comprehensive analysis and reporting features to help testers interpret test results effectively. After executing a test plan, testers can use built-in listeners such as Summary Report, Aggregate Report, Response Times Over Time, etc., to visualize performance metrics and identify potential bottlenecks. Moreover, JMeter allows exporting test results in various formats including CSV, XML, and HTML for further analysis or sharing with stakeholders.

We can generate HTML report through JMeter CLI for any test executed, open cmd in the bin folder where jmeter.bat file is present and then execute the following command:

Command:  JMeter -n -t path-of-test-plan -l path-of-test-log-file -e -o path-of-output-folder        

Refer to this link to see the example of report generated and graphical representation of the logs achieved from any test executed.

Link: https://jmeter.apache.org/usermanual/generating-dashboard.html

Framework Structure and Execution:

This test script is created to perform a load test on a demo web application Conduit App with five users, each user will perform the same transaction, single iteration each.

Execution Report:

When we executed the above script, we deliberately created an error to have a brief overview of the report, statistics, and graphical representation.

Following are the snapshots of report generated through above script:

Graphical representation:

Add-ons:

While JMeter provides extensive functionality out of the box, there are several add-ons and plugins available to extend its capabilities further. Some popular add-ons include:

• JMeter Plugins: A collection of plugins providing additional functionality such as custom samplers, listeners, and visualization tools.
• Blaze Meter: Integration with Blaze Meter allows for seamless cloud-based load testing and reporting.
• WebDriver Sampler: Allows JMeter to execute Selenium scripts for performance testing web applications with real browsers.
• JSON Extractor: Enables parsing JSON responses and extracting values for further processing in test scripts.

Reference Links:

1. Download Apache JMeter: https://jmeter.apache.org/download_jmeter.cgi
2. User manual: https://jmeter.apache.org/usermanual/index.html