fix(common): prevent multi-table commits failing with metrics enabled

[1fanwang]

Describe the issue this Pull Request addresses

When one Spark driver writes several Hudi tables with metrics enabled, clearing one table's local metrics can abort another table's commit. LocalRegistry.clear() can run between containsKey() and get(), causing a concurrent metric update to fail with:

java.lang.NullPointerException: Cannot invoke "org.apache.hudi.common.metrics.Counter.add(long)" because the return value of "org.apache.hudi.common.metrics.LocalRegistry.getCounter(String)" is null

Closes #19570.

Summary and Changelog

Counter lookup now uses ConcurrentHashMap.computeIfAbsent(), so a concurrent clear cannot make it return null. The atomic lookup matches the fix proposed in #19584. This PR adds a deterministic interleaving test that reproduces the failure.

Impact

There is no public API change. Concurrent metric updates no longer fail when the local registry is cleared.

Risk Level

Low. The change replaces a compound access to an existing ConcurrentHashMap with its atomic lookup operation.

Testing

Raw failing and passing regression

$ export JAVA_HOME=$(/usr/libexec/java_home -v 17)
$ git restore --source=upstream/master --worktree hudi-io/src/main/java/org/apache/hudi/common/metrics/LocalRegistry.java
$ mvn -pl hudi-io -am -Dtest=org.apache.hudi.common.metrics.TestLocalRegistry -Dsurefire.failIfNoSpecifiedTests=false test
[ERROR] Tests run: 1, Failures: 1, Errors: 0, Skipped: 0
org.opentest4j.AssertionFailedError: Unexpected exception thrown: java.util.concurrent.ExecutionException: java.lang.NullPointerException: Cannot invoke "org.apache.hudi.common.metrics.Counter.add(long)" because the return value of "org.apache.hudi.common.metrics.LocalRegistry.getCounter(String)" is null
[INFO] BUILD FAILURE

$ git restore --source=HEAD --worktree hudi-io/src/main/java/org/apache/hudi/common/metrics/LocalRegistry.java
$ mvn -pl hudi-io -am -Dtest=org.apache.hudi.common.metrics.TestLocalRegistry -Dsurefire.failIfNoSpecifiedTests=false test
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
[INFO] BUILD SUCCESS

Full hudi-io suite

$ mvn -pl hudi-io -am test
[INFO] Tests run: 126, Failures: 0, Errors: 0, Skipped: 0
[INFO] hudi-io ............................................ SUCCESS
[INFO] BUILD SUCCESS

Documentation Update

None.

Contributor's checklist

• Read through contributor's guide. Reviewed the contributor guide and repository PR template.
• Enough context is provided in the sections above. The issue and prior implementation are linked.
• Adequate tests were added if applicable. The deterministic regression fails on upstream/master, passes on this branch, and the full hudi-io suite passes.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.15%. Comparing base (01935d1) to head (f74202b).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #19787      +/-   ##
============================================
- Coverage     78.16%   78.15%   -0.01%     
+ Complexity    33730    33728       -2     
============================================
  Files          2541     2541              
  Lines        141536   141534       -2     
  Branches      17138    17138              
============================================
- Hits         110634   110622      -12     
- Misses        23195    23201       +6     
- Partials       7707     7711       +4     

Components	Coverage Δ
hudi-common	83.59% <ø> (-0.01%)	⬇️
hudi-client	83.14% <ø> (-0.02%)	⬇️
hudi-flink	85.65% <ø> (ø)
hudi-spark-datasource	72.69% <ø> (-0.01%)	⬇️
hudi-utilities	74.52% <ø> (-0.04%)	⬇️
hudi-cli	15.06% <ø> (ø)
hudi-hadoop	70.13% <ø> (+0.01%)	⬆️
hudi-sync	75.54% <ø> (ø)
hudi-io	79.98% <100.00%> (-0.02%)	⬇️
hudi-timeline-service	83.44% <ø> (ø)
hudi-cloud	65.81% <ø> (ø)
hudi-kafka-connect	53.20% <ø> (ø)

Flag	Coverage Δ
common-and-other-modules	51.44% <100.00%> (-0.01%)	⬇️
flink-integration-tests	48.86% <100.00%> (+<0.01%)	⬆️
hadoop-mr-java-client	44.04% <100.00%> (+0.01%)	⬆️
integration-tests	13.53% <100.00%> (-0.01%)	⬇️
spark-client-hadoop-common	50.40% <100.00%> (-0.01%)	⬇️
spark-java-tests	52.19% <100.00%> (-0.02%)	⬇️
spark-scala-tests	46.70% <100.00%> (-0.03%)	⬇️
utilities	36.59% <100.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
.../org/apache/hudi/common/metrics/LocalRegistry.java	95.00% <100.00%> (-0.46%)	⬇️

... and 11 files with indirect coverage changes

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[hudi-bot]

CI report:

• f74202b Azure: SUCCESS

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