[FLINK-37748][Kubernetes Operator]Remove JDK only JVM arguments from Flink operator Helm chart

[ekazakas]

What is the purpose of the change

There is an issue with Flink Kubernetes operator where JVM reports unrecognized options. These options are:

--add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED
--add-exports=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED
--add-exports=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED
--add-exports=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED
--add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED

The above are only valid in JDK environments. When running in JRE environments, where most of the Flink applications will be running, the VM reports the following warnings:

WARNING: Unknown module: jdk.compiler specified to --add-exports
WARNING: Unknown module: jdk.compiler specified to --add-exports
WARNING: Unknown module: jdk.compiler specified to --add-exports
<...>

Brief change log

• Removed JDK only JVM options from operator Helm chart

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changes to the CustomResourceDescriptors: no
• Core observer or reconciler logic that is regularly executed: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? not applicable

[gyfora]

These were added to improve java 17 compatibility for Flink apps, will this affect that? If so having the warnings doesn't seem like a big deal

[ekazakas]

These were added to improve java 17 compatibility for Flink apps, will this affect that? If so having the warnings doesn't seem like a big deal

It should not affect it, especially if the apps are running in JRE environment. When running in JRE, these options are not taken into account at all, they simply do not exist in those environments.

P.S. The operator image itself is running in JRE environment

[gyfora]

These were added to improve java 17 compatibility for Flink apps, will this affect that? If so having the warnings doesn't seem like a big deal

It should not affect it, especially if the apps are running in JRE environment. When running in JRE, these options are not taken into account at all, they simply do not exist in those environments.

P.S. The operator image itself is running in JRE environment

This is about the Flink jobs, and the question is whether these params make Java 17 compatibility better in JDK env. If they do we should keep that and accept the warning as that doesn't hurt

[ekazakas]

It doesn't make the compatibility better, since Flink jobs do not require compiler modules. In case of very specific applications that for some reason would need to access the javac compiler and it's modules, users could specify that in env.java.opts.all. But it's up to Flink maintainers to decide whether they would agree with this change. It would avoid the unnecessarry log pollution for 99% of Flink jobs

[gyfora]

Makes sense @ekazakas thanks for the explanation :) Let's try this

[davidradl]

I see in the comment above that the below content should be kept in sync with flink-dist/src/main/resources/config.yaml.

I suggest that we amend the comment - as it will no longer be true.

[ekazakas]

I have removed this comment

[ferenc-csaky]

@gyfora we good to merge this?

[gyfora]

Thanks for the reminder @ferenc-csaky , merging