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https://issues.apache.org/jira/browse/FLINK-34148?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17809796#comment-17809796
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Sergey Nuyanzin commented on FLINK-34148:
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An interesting finding:
1. jackson 2.15.x requires maven-shade-plugin 3.4.1+ because of multirelease jar
2. Starting 3.4.1 maven-shade-plugin stopped modifying the dependency tree at
runtime when bundling dependencies
https://issues.apache.org/jira/browse/MSHADE-413
as a result now these dependencies could be seen via {{mvn dependency:tree}}
and there is no such for prev flink-shaded
I was able to reproduce the perf issue mentioned in description. And as a local
test just added exclusions for bundle dependencies in flink-benchmarks. After
that perf issue disappeared. It looks like it could be the root cause.
There are several ways to fix it
1) Add such exclusions everywhere where it is required (however it looks hacky)
2) Revert it to flink-shaded 1.17.0 (however need to keep in mind that it
brings netty 4.1.91 which is lower than required by jdk21, even though current
ci passes for jdk21 there could be a hidden issue)
3) Add fix to flink-shaded with making bundled deps optional like it was done
within FLINK-28016 and create a new release of flink-shaded (1.18.1 e.g.) (The
issue here is that it could take a couple of months to get enough binding votes
before the release happens)
> Potential regression (Jan. 13): stringWrite with Java8
> ------------------------------------------------------
>
> Key: FLINK-34148
> URL: https://issues.apache.org/jira/browse/FLINK-34148
> Project: Flink
> Issue Type: Improvement
> Components: API / Type Serialization System
> Reporter: Zakelly Lan
> Priority: Blocker
> Fix For: 1.19.0
>
>
> Significant drop of performance in stringWrite with Java8 from commit
> [881062f352|https://github.com/apache/flink/commit/881062f352f8bf8c21ab7cbea95e111fd82fdf20]
> to
> [5d9d8748b6|https://github.com/apache/flink/commit/5d9d8748b64ff1a75964a5cd2857ab5061312b51]
> . It only involves strings not so long (128 or 4).
> stringWrite.128.ascii(Java8) baseline=1089.107756 current_value=754.52452
> stringWrite.128.chinese(Java8) baseline=504.244575 current_value=295.358989
> stringWrite.128.russian(Java8) baseline=655.582639 current_value=421.030188
> stringWrite.4.chinese(Java8) baseline=9598.791964 current_value=6627.929927
> stringWrite.4.russian(Java8) baseline=11070.666415 current_value=8289.95767
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