microsoft / microsoft/gctoolkit
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
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- Dominant language
- Java
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Description
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.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by loading the attached GC log and comparing the Java 17 Parallel Old/New records with the Java 11 behavior described in the report. Investigate the assumption that every GC collection is followed by a new total heap size record; done means the 50GB-versus-56GB discrepancy and the promoted/young-generation calculations are corrected.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- java
- Domain
- devtools, performance
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100