Load and Analyze Performance Metrics with Jmeter — DS

Load and Analyze Performance Metrics

A Thread Group in JMeter defines the number of users (threads), the ramp-up time, and the number of iterations or loops for the test. Here’s how to create one:

1. Right click on the Test Plan

• Add
• Threads
• Thread Group

2. Configure the number of threads and ramp-up time. Ramp-up time is the time which measures the time JMeter will take to start all the threads.

Advanced Thread Group Methods

1) Ultimate Thread Group

The Ultimate Thread Group allows us to define complex load patterns with different user ramp-up times, hold times, and shutdown times. It is designed for more granular control over the load testing process.

2) Concurrency Thread Group

The Concurrency Thread Group focuses on maintaining a constant number of concurrent users while simulating a real-world scenario.

Assertions:

• Validate response text, response code, response message, or headers.
• Can assert partial or full matches of text/regular expressions.

Usage Example: You want to check if the response contains the word “success”. You can add a Response Assertion to the HTTP Request sampler, select the “Response Text” field, and add “success” to the pattern.

Configurations:

• Pattern Matching Rules: Contains
• Matches
• Equals
• Substring
• Field to Test

Beanshell

Beanshell in JMeter is a powerful feature that allows you to execute dynamic and custom logic during your test execution using a lightweight Java-like scripting language called BeanShell

Timers in Jmeter

Timers in JMeter are essential for controlling the pace of requests made to the server during a test. By default, JMeter sends requests without any delays between them, which isn’t realistic for simulating real user behavior. Timers allow you to introduce pauses (or think times) between requests to better simulate user interactions and create more realistic load scenarios.

These two timers we majorly use i.e ;

1) Constant Timer

In real life, users typically take time between actions like navigating pages, filling out forms, etc. The Constant Timer allows us to add pause, simulating this “think time” in the test.

Good to Read:- How to Create Test Plan in Jmeter?| Test Plan in Jmeter

2) Gaussian Random Timer

Normal Distribution of Delays: Delays are generated using a Gaussian distribution, with most delays close to the mean value.

Two Configurable Parameters:

• Deviation: Controls how much the delay varies around the mean.
• Constant Delay Offset: Defines the base (minimum) delay added to the Gaussian random delay.

Controllers for Modules Wise Metrics

In JMeter, controllers help to manage the flow of the test plan and organize the execution of requests. They allow testers to design complex testing scenarios by controlling the order, iteration, and conditions under which test elements are executed There are two main controllers which we use in jmeter : –

1) Transaction Controller

It Measures the time taken by all the requests as a single transaction. it is Useful for reporting the overall time for a series of requests.

2) Simple Controller

• Groups requests or samplers together.
• Does not influence execution behavior directly.
• Useful for organizing your test plan.

Importance of Regular Expression

Regular expressions (regex) play a critical role in JMeter for handling dynamic data, extracting values, and applying assertions. They help in parsing responses, parameterizing requests, and validating the correctness of response content. In below Screenshot Token value is getting extracted

In JMeter, the HTTP Cookie Manager is essential for managing and simulating how a browser handles cookies during a test. Cookies are used in web applications to maintain sessions and track user state, such as authentication and other session-related information. The HTTP Cookie Manager helps capture and reuse these cookies, ensuring that your test plan accurately mimics real-world browser behavior.

Good to Read:- API Performance Testing Using Jmeter | Jmeter Api Testing

Importance of HTTP Cookie Manager in Capturing Sessions

• Session Management
• Handling Multiple User Sessions
• Automatic Cookie Storage and Replay
• Managing Cookies Across Multiple Domains

Originally published at https://www.devstringx.com on July 23, 2024