Fix: Downgrade optional plugin dependency warning to a single info log (#21322)

[lazyfetch]

Description

Changed a multi-line WARN log to a single INFO log when an optional plugin is missing during startup. This prevents confusing, fragmented output and explicitly identifies the dependency as "optional", as requested by the maintainers.

Taking this over with permission from @dzane17.

Related Issues

Resolves #21322

Check List

• Functionality includes testing. (Note: Trivial logging string change, no new tests required).
• API changes companion pull request created, if applicable.
• Public documentation issue/PR created, if applicable.

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[github-actions]

PR Reviewer Guide 🔍

(Review updated until commit 4e333fb)

Here are some key observations to aid the review process:

🧪 PR contains tests

🔒 No security concerns identified

✅ No TODO sections

🔀 No multiple PR themes

⚡ No major issues detected

[github-actions]

PR Code Suggestions ✨

Latest suggestions up to 4e333fb

Explore these optional code suggestions:

Category	Suggestion	Impact
General	Simplify multi-line log message The log message uses string concatenation with the '+' operator for a multi-line message. Consider using a single string literal or text blocks (Java 13+) for better readability and to avoid potential issues with string concatenation in logging statements. server/src/main/java/org/opensearch/plugins/PluginsService.java [628-633] logger.info( - "Missing optional plugin [{}], dependency of [{}]. " - + "Some features of this plugin may not function without the dependencies being installed.", + "Missing optional plugin [{}], dependency of [{}]. Some features of this plugin may not function without the dependencies being installed.", dependency, name ); Suggestion importance[1-10]: 4 __ Why: The suggestion correctly identifies that the string concatenation with + can be simplified into a single string literal. While this improves readability slightly, the impact is minimal since both approaches are functionally equivalent and the current code is already clear.	Low

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Previous suggestions

Suggestions up to commit 2c54bae

Category	Suggestion	Impact
General	Simplify multi-line log message The log message uses string concatenation with the '+' operator for a multi-line string. Consider using a single string literal or text blocks (Java 15+) for better readability and to avoid potential issues with string concatenation in logging statements. server/src/main/java/org/opensearch/plugins/PluginsService.java [628-633] logger.info( - "Missing optional plugin [{}], dependency of [{}]. " - + "Some features of this plugin may not function without the dependencies being installed.", + "Missing optional plugin [{}], dependency of [{}]. Some features of this plugin may not function without the dependencies being installed.", dependency, name ); Suggestion importance[1-10]: 4 __ Why: The suggestion correctly identifies that the string concatenation with + can be simplified into a single string literal. However, this is a minor style improvement that doesn't significantly impact functionality, readability, or performance. The existing code is already clear and functional.	Low

Suggestions up to commit d404403

Category	Suggestion	Impact
General	Use parameterized logging for performance Use parameterized logging instead of string concatenation to improve performance and avoid unnecessary string creation when the log level is disabled. This is a best practice for logging frameworks. server/src/main/java/org/opensearch/plugins/PluginsService.java [628-629] -logger.info("Missing optional plugin [" + dependency + "], dependency of [" + name + "]. " + - "Some features of this plugin may not function without the dependencies being installed."); +logger.info("Missing optional plugin [{}], dependency of [{}]. Some features of this plugin may not function without the dependencies being installed.", dependency, name); Suggestion importance[1-10]: 7 __ Why: The suggestion correctly identifies that parameterized logging is a best practice that avoids unnecessary string concatenation and object creation. The existing_code matches lines 628-629 in the PR diff, and the improved_code accurately shows the parameterized version. This is a valid performance and maintainability improvement.	Medium

[github-actions]

❌ Gradle check result for d404403: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

Persistent review updated to latest commit 2c54bae

[github-actions]

❌ Gradle check result for 2c54bae: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

Persistent review updated to latest commit 4e333fb

[github-actions]

✅ Gradle check result for 4e333fb: SUCCESS

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 73.45%. Comparing base (3d1fd3f) to head (4e333fb).
⚠️ Report is 46 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #21891      +/-   ##
============================================
- Coverage     73.51%   73.45%   -0.07%     
+ Complexity    75357    75268      -89     
============================================
  Files          6028     6026       -2     
  Lines        342003   341906      -97     
  Branches      49185    49181       -4     
============================================
- Hits         251434   251143     -291     
- Misses        70554    70751     +197     
+ Partials      20015    20012       -3     

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