Can you give some real world examples when to use JFR custom events? The Minecraft example is not helpful when I know nothing about Minecraft.
* Monitoring invocations of a REST API: https://www.morling.dev/blog/rest-api-monitoring-with-custom...
* Tracking SQL queries issued by your ORM: https://www.javaadvent.com/2021/12/keep-your-sql-in-check-wi...
The latter is about injecting event-emitting code with a Java Agent rather than manually implementing custom events (latest Hibernate ORM version comes with JFR support OOTB, too).
Yep, we use custom JFR events to track API calls and correlate them to other built-in JFR events and statistics (garbage collection, memory use, allocations, CPU use, deadlocks, etc).