SOLR-11281: Remove the diagnostic additions and apply a patch from Jason Gerlowski.

solr/core/src/java/org/apache/solr/metrics/reporters/SolrSlf4jReporter.java

@@ -57,7 +57,6 @@ public class SolrSlf4jReporter extends FilteringSolrMetricReporter {
   private String logger = null;
   private Slf4jReporter reporter;
   private boolean active;
-  private DiagnosticMetricRegistry diagnosticMetricRegistry;
 
   /**
    * Create a SLF4J reporter for metrics managed in a named registry.
@@ -85,10 +84,8 @@ public class SolrSlf4jReporter extends FilteringSolrMetricReporter {
     } else {
       instancePrefix = instancePrefix + "." + registryName;
     }
-    MetricRegistry registry = metricManager.registry(registryName);
-    diagnosticMetricRegistry = new DiagnosticMetricRegistry(registry);
     Slf4jReporter.Builder builder = Slf4jReporter
-        .forRegistry(diagnosticMetricRegistry)
+        .forRegistry(metricManager.registry(registryName))
         .convertRatesTo(TimeUnit.SECONDS)
         .convertDurationsTo(TimeUnit.MILLISECONDS);
 
@@ -133,43 +130,4 @@ public class SolrSlf4jReporter extends FilteringSolrMetricReporter {
   boolean isActive() {
     return active;
   }
-
-  // for unit tests
-  int getCount() {
-    return diagnosticMetricRegistry != null ? diagnosticMetricRegistry.count : -1;
-  }
-
-  static class DiagnosticMetricRegistry extends MetricRegistry {
-    MetricRegistry delegate;
-    int count = 0;
-    DiagnosticMetricRegistry(MetricRegistry delegate) {
-      this.delegate = delegate;
-    }
-
-    @Override
-    public SortedMap<String, Counter> getCounters(MetricFilter filter) {
-      return delegate.getCounters(filter);
-    }
-
-    @Override
-    public SortedMap<String, Histogram> getHistograms(MetricFilter filter) {
-      return delegate.getHistograms(filter);
-    }
-
-    @Override
-    public SortedMap<String, Meter> getMeters(MetricFilter filter) {
-      return delegate.getMeters(filter);
-    }
-
-    @Override
-    public SortedMap<String, Timer> getTimers(MetricFilter filter) {
-      return delegate.getTimers(filter);
-    }
-
-    @Override
-    public SortedMap<String, Gauge> getGauges(MetricFilter filter) {
-      count++;
-      return delegate.getGauges(filter);
-    }
-  }
 }

solr/core/src/test/org/apache/solr/metrics/reporters/SolrSlf4jReporterTest.java

@@ -17,6 +17,7 @@
 
 package org.apache.solr.metrics.reporters;
 
+import java.lang.invoke.MethodHandles;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.Map;
@@ -34,14 +35,18 @@ import org.apache.solr.metrics.SolrMetricManager;
 import org.apache.solr.metrics.SolrMetricReporter;
 import org.apache.solr.util.TestHarness;
 import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  *
  */
 public class SolrSlf4jReporterTest extends SolrTestCaseJ4 {
+  private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
 
   @Test
   public void testReporter() throws Exception {
+    ensureLoggingConfiguredAppropriately();
     LogWatcherConfig watcherCfg = new LogWatcherConfig(true, null, null, 100);
     LogWatcher watcher = LogWatcher.newRegisteredLogWatcher(watcherCfg, null);
     watcher.setThreshold("INFO");
@@ -78,19 +83,20 @@ public class SolrSlf4jReporterTest extends SolrTestCaseJ4 {
     }
     Thread.sleep(5000);
 
-    int count1 = ((SolrSlf4jReporter)reporter1).getCount();
-    assertTrue("test1 count should be greater than 0", count1 > 0);
-    int count2 = ((SolrSlf4jReporter)reporter2).getCount();
-    assertTrue("test2 count should be greater than 0", count1 > 0);
-
     SolrDocumentList history = watcher.getHistory(-1, null);
     // dot-separated names are treated like class names and collapsed
     // in regular log output, but here we get the full name
     if (history.stream().filter(d -> "solr.node".equals(d.getFirstValue("logger"))).count() == 0) {
-      fail("count1=" + count1 + ", count2=" + count2 + " - no 'solr.node' logs in: " + history.toString());
+      fail("No 'solr.node' logs in: " + history.toString());
     }
     if (history.stream().filter(d -> "foobar".equals(d.getFirstValue("logger"))).count() == 0) {
-      fail("count1=" + count1 + ", count2=" + count2 + " - no 'foobar' logs in: " + history.toString());
+      fail("No 'foobar' logs in: " + history.toString());
+    }
+  }
+
+  private static void ensureLoggingConfiguredAppropriately() throws Exception {
+    if (! log.isInfoEnabled()) {
+      fail("Test requires that log-level is at-least INFO, but INFO is disabled");
     }
   }
 }