As defined on the home page, Quarkus is “a Kubernetes Native Java stack tailored for OpenJDK HotSpot and GraalVM.” Since I’m a big fan of OpenJ9, I’ve quickly measured memory usage of my reactive sample application where I run a microservice once with OpenJ9 and once with HotSpot.
OpenJ9 is a Java JVM that was open sourced from IBM 2-3 years ago. It’s basically the same JVM that IBM uses in hundreds of products and offerings. The nice thing is that compared to Hotspot, it not only provides a 42% faster startup time, but also a 66% smaller memory footprint. Check out the documentation.