[11u] Discussion: Backporting features and larger fixes for JFR to JDK 11 Update releases

[Langer, Christoph]

Dear all,

Andrew and I have been discussing what we should do regarding incoming requests to backport JFR features to JDK 11 Updates.

For example, there are currently wishes to backport:
JDK-8185525: Add JFR event for DictionarySizes [0]
JDK-8225797: OldObjectSample event creates unexpected amount of checkpoint data [1]

While the first one introduces a new (probably useful) JFR event, the second one makes the existing 'Old Object Sample ' usable at all for memory leak analysis.

Bot have in common that the changes are quite extensive and need manual modifications. Especially the latter one also has quite some prerequisite changes which ought to be backported as well.

So, apart from the decision about letting these very bugfixes into jdk11u, there's a general question about how to handle incoming JFR related backport requests that go beyond simple bugfixes. Shall we rather try to pull in more stuff to make the JFR tooling more usable while putting stability of JDK updates at higher risk? Or shall we be conservative here and rather reject things if in doubt? Any thoughts or comments from the community?

Thanks
Christoph

[0] https://bugs.openjdk.java.net/browse/JDK-8185525
[1] https://bugs.openjdk.java.net/browse/JDK-8225797