DGS-20118: Upgrade log4j to log4j2

[GunalKupta]

What

• AK upgraded to log4j2: KAFKA-9366: Upgrade log4j to log4j2 apache/kafka#17373
• XML files were generated using Apache log4j migration tool with manual edits to restore comments

Checklist

• Contains customer facing changes? Including API/behavior changes
• Is this change gated behind feature flag(s)?
  • List the LD flags needed to be set to enable this change
• Did you add sufficient unit test and/or integration test coverage for this PR?
  • If not, please explain why it is not required
  • No code change
• Does this change require modifying existing system tests or adding new system tests?
  • If so, include tracking information for the system test changes

References

JIRA: DGS-20118

Test & Review

Ran bin/schema-registry-start config/schema-registry.properties locally and verified that the logs look identical when run in this branch and master branch

Open questions / Follow-ups

[confluent-cla-assistant]

🎉 All Contributor License Agreements have been signed. Ready to merge.
_{Please push an empty commit if you would like to re-run the checks to verify CLA status for all contributors.}

[Copilot]

Pull Request Overview

This pull request upgrades the code to use log4j2 while updating protobuf generated code accordingly. In addition, the changes update method calls and builder types in the WidgetProto and WidgetProto2 classes, and clarify doc comments in Decimal message types.

• Replaces calls to GeneratedMessageV3 with GeneratedMessage.
• Updates usage of SingleFieldBuilderV3 to SingleFieldBuilder.
• Enhances documentation by clarifying the semantics of the precision field in Decimal types.

Reviewed Changes

Copilot reviewed 8 out of 22 changed files in this pull request and generated no comments.

File	Description
schema-rules/src/test/java/io/confluent/kafka/schemaregistry/rules/WidgetProto2.java	Updates method calls for string writing and changes builder type; removes overrides for unknown field handling.
schema-rules/src/test/java/io/confluent/kafka/schemaregistry/rules/WidgetProto.java	Switches method calls and builder types similarly, and removes unknown field override methods.
protobuf-types/src/main/java/io/confluent/protobuf/type/DecimalOrBuilder.java	Improves the comment describing the precision field.
protobuf-types/src/main/java/io/confluent/protobuf/type/Decimal.java	Updates the doc comments for precision in several locations.

Files not reviewed (14)

• avro-serializer/src/test/resources/log4j.properties: Language not supported
• avro-serializer/src/test/resources/log4j2.xml: Language not supported
• benchmark/src/main/resources/log4j.properties: Language not supported
• benchmark/src/main/resources/log4j2.xml: Language not supported
• config/log4j.properties: Language not supported
• config/log4j2.xml: Language not supported
• core/src/main/resources/log4j.properties: Language not supported
• core/src/main/resources/log4j2.xml: Language not supported
• core/src/test/resources/log4j.properties: Language not supported
• core/src/test/resources/log4j2.xml: Language not supported
• protobuf-converter/src/test/resources/log4j.properties: Language not supported
• protobuf-converter/src/test/resources/log4j2.xml: Language not supported
• schema-rules/src/test/resources/log4j.properties: Language not supported
• schema-rules/src/test/resources/log4j2.xml: Language not supported

Comments suppressed due to low confidence (2)

schema-rules/src/test/java/io/confluent/kafka/schemaregistry/rules/WidgetProto2.java:3318

• The removal of the overridden setUnknownFields and mergeUnknownFields methods may affect unknown fields handling. Please verify that this change does not introduce regressions in message parsing behavior.

      @java.lang.Override

schema-rules/src/test/java/io/confluent/kafka/schemaregistry/rules/WidgetProto.java:3015

• The removal of the overridden setUnknownFields and mergeUnknownFields methods could impact the handling of unknown fields. Confirm that this change is intentional and does not compromise message consistency.

      @java.lang.Override

[rayokota]

Left a minor comment

[sonarqube-confluent]

Analysis Details

0 Issues

• 0 Bugs
• 0 Vulnerabilities
• 0 Code Smells

Coverage and Duplications

• No coverage information (74.00% Estimated after merge)
• No duplication information (2.10% Estimated after merge)

Project ID: schema-registry

View in SonarQube

[rayokota]

Thanks @GunalKupta , LGTM