Comparing JVM performance; Zulu, OpenJDK, Oracle JDK, GraalVM CE

There are many different choices for a JVM for your Java application. Which would be the best to use? This depends on various factors. Performance being an important one. Solid performance research however is difficult. In this blog post I'll describe a setup I created to perform tests on different JVMs at the same time and show some interesting results! I also looked at the effect of resource isolation (assigning specific CPUs and memory to the process). This effect was negligible. My test application consisted of a reactive (non-blocking) Spring Boot REST application and I've used Prometheus to poll the JVMs and Grafana for visualization.

Below is an image of the used setup. Everything was running in Docker containers except SoapUI.

Monitoring Spring Boot applications with Prometheus and Grafana

In order to compare the performance of different JDKs for reactive Spring Boot services, I made a setup in which a Spring Boot application is wrapped in a Docker container. This makes it easy to create different containers for different JDK's with the same Spring Boot application running in it. The Spring Boot application exposes metrics to Prometheus. Grafana can read these metrics and allows to make nice visualizations from it. This blog post describes the setup. A next post will show the results. You can download the code here (in the complete folder). To indicate how easy this is, getting this setup up and running and write this blog post took me less than 1.5 hours total. I did not have much prior knowledge on Prometheus and Grafana save for a single workshop at AMIS by Lucas Jellema.