The best insight into the operation of the JVM is now obtained via a single mechanism, JFR (https://dev.java/learn/jvm/jfr/), the JDK's observability and monitoring engine. It records a whole lot of event types: https://sap.github.io/SapMachine/jfrevents/
See here for examples related to tracking memory: https://www.morling.dev/blog/tracking-java-native-memory-wit...