If you're using CSV data in your JMeter script, you can process the input data in parallel across multiple test engines. Azure Load Testing enables you to configure a test to split the data evenly across all engine instances.
For example, if you have a large customer CSV input file, and the load test runs on 10 parallel test engines, each instance will process 1/10th of the customers.
Azure Load Testing will automatically split and process the data across all test engines. You don't have to make any modifications to the JMX test script.
Learn more about splitting input data across instances.