Hi, Last September, Volker shared the observation that we have Hotspot-internal MBeans in sun.management which are strongly encapsulated and not used internally by OpenJDK besides their unit tests:
https://www.mail-archive.com/core-libs-dev@openjdk.org/msg19878.html A summary of the email thread: Mandy pointed out: We added these HotSpot internal MBeans in JDK 5 to expose the internal > metrics. Most of these internal metrics are exposed via jstat tool too. > We didn't receive much feedback regarding these HotSpot internal MBeans. > Removing them is fine and good cleanup effort. Alan made a similar point: It's left over from experiments on exposing some internal metrics, I think > during JDK 5. It's code that should probably have been removed a long time > ago. Kirk P raised a concern: It would be a shame to lose these metrics because many of them have been > very > useful over time and some would be even more useful with some > modifications. > To which Mandy responded: What we're referring to is to remove sun.management.Hotspot*, the internal > MBeans which are never exposed and registered in the platform MBeanServer. > The internal metrics in HotSpot VM should be retained as they are exposed > through other ways like jstat, GC logs, etc. The email thread seems to have ended here without further action taken. My interpretation of the above is that we have a consensus that these Hotspot-internal MBeans can be removed. Since I was not part of the initial discussion and some time has passed, I'd like some confirmation that my interpretation is correct. Would a PR to remove these APIs be welcome? (This would remove HotspotInternalMBean, HotspotMemoryMBean, HotspotRuntimeMBean, HotspotThreadMBean, with associated implementation, factory methods, tests and probably also some native code in libmanagement. Details can be discussed in a PR) Cheers, Eirik.
