Java 17 Parallel Old/New Parsing has altered from JDK 11, impacting what is reported as promoted bytes and what is reported in young gen

[karianna]

Describe the bug
Censum seems to be reporting on -xmn values as opposed to -xmx values but that is a red herring. What has actually changed is that after a gc collection record there's no longer always a new gc total heap size record.

To Reproduce
Load the attached log, you'll note that full heap seems to be at 50GB when it should be 56GB, there are other calculations challenges.

[karianna]

java17_parallel_parsing_issue.txt

[karianna]

@kirk-microsoft as discussed on the call. I'll let you take a look first before we 'fix' and add this to the test data