Preserve underscores in resource group metric tags

[efegokdemir]

Summary

Fixes the monitor's resource-group lookup after Micrometer formats metric tag names.

Changes

• Retain Micrometer-compatible MetricsUtil.formatString behavior.
• Resolve a formatted resource-group metric tag against the configured resource-group names in monitor-side processing.
• Preserve the formatted value when there is no match or when multiple configured names map to the same formatted value.
• Add regression coverage for underscore preservation and ambiguous matches.

Testing

• mvn -pl core -am -Dtest=MetricsUtilTest -DskipITs -Dcheckstyle.skip=true test -q — passed.
• git diff --check — passed.

Notes

The implementation follows the requested matching approach: it keeps canonical formatting and resolves back to a configured resource-group name only when the formatted value has one unique match.

[dlmarion]

Removing the MetricUtil.formatString formatting is likely not the correct approach here as the formatting is consistent with Micrometer's suggested format. Instead, we probably need a method that takes the resource group tag value and the set of valid resource group names and returns the match.

[efegokdemir]

Updated the PR description to match the current implementation. Micrometer-compatible formatting is retained; monitor-side processing now resolves the formatted tag against configured resource-group names and preserves ambiguous/non-matching values. The focused MetricsUtilTest and reactor test command pass, and git diff --check passes. Please re-review the current HEAD when convenient.

[dlmarion]

I don't think this behavior is correct. It's returning a resource group name that is not valid.

[efegokdemir]

Addressed the current-head feedback in aa8eff8470: resource-group resolution now returns a name only for a unique configured match. Ambiguous or unknown formatted tags are rejected before constructing ResourceGroupId or updating the queued-resource-group map, so the monitor cannot surface a non-configured resource group. Added the unknown-name regression. Validation: mvn -pl core -am -Dtest=MetricsUtilTest -DskipITs -Dcheckstyle.skip=true test -q, monitor compile, and git diff --check passed.

[efegokdemir]

Updated eae6317 to follow the requested zero/ambiguous-match semantics: MetricsUtil now throws an informative IllegalStateException unless exactly one configured resource group matches. The monitor callers catch it, log the invalid tag, and skip that metric instead of retaining an invalid name. Added/updated focused resolution tests.

Validation: mvn -pl core -am -Dtest=MetricsUtilTest -DskipITs -Dcheckstyle.skip=true test -q passed; git diff --check passed.

[efegokdemir]

Updated in c3fbf79. Unique configured matches still resolve normally; zero or ambiguous matches now retain the monitor’s unknown resource-group value while logging the warning, rather than dropping the metric or exposing an unconfigured name.

Validation: mvn -pl core -am -Dtest=MetricsUtilTest -DskipITs -Dcheckstyle.skip=true test -q, monitor compile with mvn -pl server/monitor -am -DskipTests -Dcheckstyle.skip=true compile -q, and git diff --check passed.

[efegokdemir]

Simplified the resource-group resolution as requested. The formatting-to-configured-name lookup now stays local to the monitor path, removes the core utility API and labeled loop, skips invalid metric-table entries, and retains the unknown fallback for queued-compaction metrics. Added focused resolution coverage.

Validation: mvn -pl server/monitor -am -DskipITs -Dcheckstyle.skip=true -Dspotless.check.skip=true -Dtest=SystemInformationTest -Dsurefire.failIfNoSpecifiedTests=false test passed; compilation/formatting completed successfully; git diff --check passed.

[efegokdemir]

The existing branch has been updated at with the requested unique/ambiguous/unknown resource-group handling and fallback. Focused tests, monitor compilation, formatting, and passed. Please re-review the current head.