High monitor usage due to Finalizer.add

[Karasiq]

Hello! We updated our project to use the 5.8.0 with fixed #1211
But we still have too much monitor usage due to Memory finalizers. (and therefore high latency of api calls)

We solved it the with usage of the sun.misc.Cleaner instead of finalizers:

Code: https://github.com/wavesplatform/Waves/pull/3503/files
Obviously this solution is not very clean, since it's an internal Sun class, but it standard counterpart java.lang.ref.Cleaner is available only since Java 9.

[Karasiq]

Also same issue with LinkedReference.track

[matthiasblaesing]

Could you please have a look/measurement at #1402? It might help with the issue.

[matthiasblaesing]

Seems there is no more interest in this.