How to Implement Batched Request Delays in JMeter

Discover how to manage and optimize your JMeter testing by implementing batched requests with delays in between. Learn how to set up your tests effectively for large loads!
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How to Implement Batched Request Delays in JMeter: A Step-by-Step Guide

When performing load testing with JMeter, you may encounter situations where you need to send a significant number of requests but want to control the frequency of those requests to simulate real-world scenarios accurately. One such scenario might involve sending thousands of POST requests — say, 2,000, 5,000, or even 10,000 — while introducing a delay after every set of 100 requests. In this guide, we’ll explore how to implement this effectively using JMeter, ensuring your tests are both efficient and realistic.

The Problem Breakdown

The goal is to send requests in batches with a specified delay. For example, if we have a thread group with:

Number of Threads (users): 5

Loop Count: 400, 1000, and 2000

After sending every 100 requests (totaling 20 requests per thread), we want to introduce a delay of 5 seconds before sending the next batch. This approach helps simulate bursts of activity while allowing time for the server to process requests.

The Solution

Step 1: Setting Up Your JMeter Thread Group

Open JMeter and create a new test plan.

Add a Thread Group:

Set the Number of Threads (users) to 5.

Include the Loop Count according to your testing need (e.g., 400, 1000, or 2000).

Step 2: Introducing the JSR223 Timer

To implement the required delay after every 100 requests, we will be using a JSR223 Timer. This timer allows us to control pauses dynamically based on our conditions.

Add a JSR223 Timer to your HTTP request sampler.

Inside the JSR223 Timer, you can add the following code:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Managing the Counter

The code above checks if the counterForDelay is divisible by 100. If this condition is true, it imposes a delay of 10 seconds before proceeding to the next set of requests. You will need to create and manage this variable.

Add a user-defined variable called counterForDelay in your Thread Group.

Increment this variable after each request to keep track of how many requests have been sent. You can use a Beanshell PreProcessor or a JSR223 PreProcessor to handle this:

[[See Video to Reveal this Text or Code Snippet]]

Step 4: Validating Your Setup

It's crucial to validate that everything is working correctly:

Run your test and observe the results.

Check the View Results Tree listener or the Summary Report listener to ensure requests are being sent in batches with the desired delays.

Conclusion

Implementing batched requests with delays in JMeter can optimize your load testing process considerably. By following the steps outlined above, you can effectively simulate realistic load scenarios that include timely pauses, ensuring that the server has adequate time to handle incoming requests.

Remember, meticulous setup and validation are vital to achieving the desired testing outcomes. By introducing the right delays, you can mimic user behavior more authentically, ultimately leading to better test results and insights.

Feel free to reach out if you have any questions or need further assistance on JMeter testing techniques!