Kafka is a successful messaging system; any company can use it in many powerful ways. A crucial part of Kafka is the capability to transport a message from producers to consumers. Imagine you have a Spring Boot Microservice that calculates the price. You could let this service read the price details from Kafka. Once the cost is calculated, you could send the record back to your Kafka messaging layer, and a consumer service could store the new price in a database.
Why Kafka Load Testing?
Response Time - Check latency under normal and peak load conditions
Availability - Check if system remains available if you introduce some chaos
Resilience - Check if messages get lost during chaos or high-load scenarios
Sizing - Check if your Kafka backend can handle the expected transaction volumes
Observability - Check if your monitoring platform works as intended and identifies slowdowns or bottlenecks
JMeter
JMeter, a popular load-testing tool, does not support load testing of Kafka producers and consumers out of the box. Luckily, there is a plugin that will help integrate your JMeter tests for Kafka environments. In Kafka, there is a producer and consumer side, and they work to allow you to enter these events and view them later on. JMeter is a performance testing tool that assesses application response times and provides results based on the findings.
Pepper Box for Kafka Load Testing
As JMeter doesn't support testing on Kafka with its base features, we have to turn to a plugin that allows for this testing. A plugin called "Pepper-Box" created by the user Raladev on GitHub bridges this gap between JMeter and Kafka. The plugin allows for testing on the producer and consumer side of Kafka and still supports the reports JMeter creates after the test runs. As it simplifies testing on Kafka, it also is a straightforward method of implementing the plugin. There isn't much past downloading a jar file and ensuring the configurations match your JMeter designs. This leads to more time for creating these tests on Kafka and analyzing and fixing any issues you may find.
One important thing that using JMeter on Kafka aids in is the load amount. Kafka is usually used with very high volume and is not typical for small environments. This leads to much traffic and a significant load test to simulate regular activity. Among other performance testing tools, JMeter supports distributed testing, which supports extensive tests where the number of transactions can be massive. This distributed testing makes JMeter the perfect match for Kafka as its support for extensive load tests assists with a large amount of traffic Kafka sees.
In summary, Kafka needs to have the ability to be load-tested as it can be a critical part of a company's operations. Despite JMeter not supporting this application out of the box, the Pepper-Box plugin bridges this gap between the two. It allows JMeter to run distributed tests on the large environments Kafka tends to operate in and streamlines the installation with clear instructions on GitHub and very few steps to get the plugin up and running.
You can find the plugin available at GitHub - raladev/load: Load Testing scripts and have to download the necessary jar files to get started.
Keep up the great work! Happy Performance Engineering!