Book Image

Master Apache JMeter - From Load Testing to DevOps

By : Antonio Gomes Rodrigues, Bruno Demion (Milamber), Philippe Mouawad
Book Image

Master Apache JMeter - From Load Testing to DevOps

By: Antonio Gomes Rodrigues, Bruno Demion (Milamber), Philippe Mouawad

Overview of this book

Load tests help identify the maximum number of requests a software system can handle. One popular open source tool for load testing is JMeter. By leveraging the features and capabilities of JMeter, you can perform extensive load testing and fix issues in your application before they become problematic. This book is written by JMeter developers and begins by discussing the whole process, including recording a script, setting it up, and launching it, enabling you to almost immediately start load testing. You'll learn the best practices that you must follow while designing test cases. You'll also explore the different protocols offered by JMeter through various real-world examples. Finally, you'll see how to integrate JMeter into the DevOps approach and create professional reports. You'll discover ways to use the eco-system of JMeter to integrate new protocols, enrich its monitoring, and leverage its power through the use of the cloud. By the end of this book, you'll know all that's needed to perform comprehensive load testing on your applications by using all the best practices and features of JMeter.
Table of Contents (14 chapters)

How Timer Scope Works

Timers are important to simulate think time in our script. Think time is the time a user takes between two interactions with the application to do things such as the following:

  • Read screen content
  • Enter login and password
  • Enter order form data

To avoid unexpected behavior, it's critical to understand how and when Timers are executed.

There are two rules, and these rules apply regardless of the location of the timer.

Rule 1: Timers Are Executed before Each Sampler in Their Scope

For example, consider the following script:

Figure 4.6: Our script with one timer

This script will be executed in the following order:

Figure 4.7: Execution order of our script with one timer

As we can see, Timer1 is:

  • Executed three times because of the scoping rule
  • Executed once before Sampler1
  • Executed once before Sampler2
  • Executed once before Sampler3

Rule 2: If There Is More Than One Timer in the Scope, All the Timers Will Be Processed...