Load Configuration

BlazeMeter is designed to speed the iterative process of testing. Frequently changed parameters can be controlled (overridden) from within the BlazeMeter UI or API, eliminating the need to edit hard-coded values in your scripts and re-upload them between tests.

• Override Settings
• Disable Overrides
• Select Total Users
• Configure Duration or Iterations
• Configure Ramp Up Time and Steps
• Limit Requests per Second (RPS)
• Change RPS Limits During Test

Override Settings

In the Load Configuration section, you can override the number of users, test duration and ramp up.

Follow these steps:

1. In the Performance tab, open a test or create a new test.
2. In the Configuration tab, scroll down to the Load Configuration section.
3. Enter numbers into the fields for Total Users, Duration and Ramp up Time.

4. (Optional) For Limit RPS and Ramp up Steps, expand the drop-down to choose a pre-selected popular configuration.

   

In a multi-test scenario, you can also set overrides for individual tests that run as part of the multi-test. However, if overrides are disabled in a multi-test, the values will be taken from the original script of each single test.

Disable Overrides

If you do not want to use any overrides, instead relying on the configuration in your original script, you can disable any and all overrides.

Follow these steps:

1. In the Performance tab, open a test or create a new test.
2. In the Configuration tab, scroll down to the Load Configuration section.
3. Click the toggle icon for each override you want to disable. Toggled right (and blue) is enabled. Toggled left (and gray) is disabled.
   Once an override is disabled, the slider bar and number field is gray and will not be applied.
   

To disable all overrides, ensure all toggles are set to the left (gray).

Overrides can only be disabled under the following conditions:

• Your account is not on a free plan.
• Your script is a JMeter script.
• If your script is not a JMeter script, then overrides will only be disabled if you upload a Taurus YAML configuration file with your script and set the YAML file as the main test file, which will automatically disable UI overrides.

Select Total Users

Select the number of users you want deployed at the peak of your test. BlazeMeter will divide this user population across the number of test engines deployed.

If your script uses multiple thread groups, the following will apply:

• If each thread group in the script is configured for 1 user (the default setting) in the Number of Threads (users) field, BlazeMeter will divide the total users evenly across the thread groups, rounding up and down as needed.
  Example:
  If you specify 10 users for 2 thread groups, each thread group will run 5 users. If you specify 6 users for 3 thread groups, each will run 2. If you run 11 users for 3 thread groups, BlazeMeter will round up (from 3.66...) and each will run 4. If you run 7 users for 3 thread groups, BlazeMeter will round down (from 2.33...) and each will run 2.
• If you specified different user numbers for each of your multiple thread groups, BlazeMeter will maintain the ratio of threads between the thread groups in the JMX to achieve the total users you specify here.
  Example:
  If your JMX has three thread groups and the Number of Threads (users) field in each of them is set to 5, 3 and 2 respectively, then a test with 1000 users specified in Load Configuration will run 500, 300 and 200 threads through those thread groups.

Tip: For advanced real-time scenarios such as increasing users, adding load, or ramping down users at a certain point during or in between execution, use either the Concurrency Thread Group or the Ultimate Thread Group in JMeter and adjust parameters dynamically. For details, see How to Change JMeter´s Load During Runtime.

Configure Duration or Iterations

You can configure your test to either run for a specified duration or for a specified number of iterations.

Follow these steps:

1. In the Performance tab, click Create Test, Performance Test.
2. Scroll down to the Load Configuration section.
3. In the Duration / Iterations section, toggling between the two options:
   • Set the duration for the entire test, in minutes. The test will run infinite iterations until the duration is met.
   • Toggle to Iterations and set the number of iterations instead. The test will run however long is required to complete all iterations.

CAUTION: There are some limitations to be aware of regarding duration and iterations:

• You cannot run a test with a duration longer than your plan limit.
• If you configure a high-iteration test using the overrides, BlazeMeter will apply a default duration of approximately 1 hour, and 10 minutes. This safeguard is to prevent abuse of the system by running an infinite-duration test. If you need to run a high-iterations test that will exceed an hour in duration, we recommend disabling overrides and setting desired values directly in your script, in which case it will be allowed to run through all iterations to completion.
• If you disable overrides and have infinite iterations (loops) set in your script, make sure you set a duration in your script.
  Example:
  If you configure a JMeter test to run infinite loops with no duration, BlazeMeter will apply a 10-second duration. This is to prevent abuse of the system by running an infinite-duration test.
• You cannot configure duration and iterations at the same time in the Overrides, but if you disable all overrides, it is possible to configure both in your script itself (JMeter, for example, allows this). If this is the case, the test will run until whichever limit (iterations or duration) is met first.

If you find that your test terminated before running its full duration, check for the above limitations first.

If executing a JMeter test, you can download the artifacts.zip file from the Logs Report. Inside is a modified_{your_script_name).jmx file. If you open that modified JMX in your local JMeter, you can see any thread group overrides that BlazeMeter may have applied to your script.

Configure Ramp Up Time and Steps

You can select how fast you want the test to ramp up. This is the elapsed time in minutes from the test start until all users are running. You can also select the number of steps for the ramp-up of your test.

To configure ramp-up time, follow these steps:

1. In the Performance tab, click Create Test, Performance Test.
2. Scroll down to the Load Configuration section.
3. Move the Ramp up Time slider or enter the number of minutes in the box.

To configure ramp-up steps, follow these steps:

1. Go to the Load Configuration section.
2. In the Ramp up Steps box, enter the value or expand the drop-down menu to select a value.

• The default value is 0, which delivers a linear ramp-up from test start until the end of ramp up time:
  
• A value of 5 delivers 20% of the peak users at the start and reaches 100% at the start of the 5th step:

Tip: For advanced real-time scenarios such as increasing users, adding load, or ramping down users at a certain point during or in between execution, use the Ultimate Thread Group in JMeter and adjust parameters dynamically. For details, see How to Change JMeter´s Load During Runtime.

Limit Requests per Second (RPS)

This setting allows you to impose a maximum requests per second (RPS).

To configure Limit RPS, follow these steps:

1. Go to the Load Configuration section.
2. In the Limit RPS box, enter the value or expand the drop-down menu to select a value.

When you use this setting, you will see a Change RPS button on your live test reports and can make changes during the test.

Change RPS Limits During Test

To Change RPS Limits during a test, follow these steps:

1. Start a test.
2. Click on the Run Time Control button in the top right corner of the reports section.
3. Click Change RPS.
   
   A dialog box will appear which lets you change the value.
4. Set the value and click Apply to send the new value to the test engines.