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https://issues.apache.org/jira/browse/HIVE-29811?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18105208#comment-18105208
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László Bodor commented on HIVE-29811:
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Attached the evaluations of my experiment with AppCDS on upstream hive
docker-compose setup: [^APPCDS-FINDINGS.pdf]
https://github.com/abstractdog/hive/commit/fbb26d5040c8e18202b563dc6ba1a61d13fc9a8d
Even though the summary was generated by claude (having the full scope of the
investigation session), the root of the reasoning is something I totally agree
with, which is: "AppCDS on HS2 with Temurin 21 base CDS produces a measurable
but operationally insignificant startup improvement."
There is still a chance that HS2 startup is slow, but it's not because of the
classloading: further optimizing it isn't worth the effort.
> HS2 slow start - try AppCDS
> ---------------------------
>
> Key: HIVE-29811
> URL: https://issues.apache.org/jira/browse/HIVE-29811
> Project: Hive
> Issue Type: Improvement
> Components: HiveServer2
> Reporter: Attila Turoczy
> Assignee: László Bodor
> Priority: Major
> Labels: cloud, modernization
> Attachments: APPCDS-FINDINGS.pdf
>
>
> HiveServer2 is slow and cold-start time is dominated by JVM class loading of
> the large *Hive/Hadoop/Tez/Calcite* class graph. Every process start
> re-parses and verifies thousands of classes from jars. The base-JDK CDS
> archive (enabled by \{{-Xshare:auto}}) covers only JDK classes.
> Hive/Hadoop/Tez/Calcite application classes are NOT archived, so they are
> re-loaded from jars every time.
> AI Recommendation:
> _AppCDS commonly reduces combined JVM + application startup by roughly 20–40%
> for large class graphs by memory-mapping pre-parsed class metadata instead of
> re-reading jars. The exact figure for HS2 should be confirmed with the
> reproduction above on a reference image; the point of the ticket is to make
> that win available and documented out of the box._
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