Log warning about gauge-re-registration

See micrometer-metricsgh-5616
jonatan-ivanov · Nov 16, 2024 · 4be104f · 4be104f
1 parent a0f4911
commit 4be104f
Showing 1 changed file with 18 additions and 0 deletions.
diff --git a/micrometer-core/src/main/java/io/micrometer/core/instrument/MeterRegistry.java b/micrometer-core/src/main/java/io/micrometer/core/instrument/MeterRegistry.java
@@ -16,6 +16,7 @@
 package io.micrometer.core.instrument;
 
 import io.micrometer.common.lang.Nullable;
+import io.micrometer.common.util.internal.logging.WarnThenDebugLogger;
 import io.micrometer.core.annotation.Incubating;
 import io.micrometer.core.instrument.Meter.Id;
 import io.micrometer.core.instrument.config.MeterFilter;
@@ -64,6 +65,9 @@
  */
 public abstract class MeterRegistry {
 
+    private static final WarnThenDebugLogger gaugeDoubleRegistrationLogger = new WarnThenDebugLogger(
+            MeterRegistry.class);
+
     // @formatter:off
     private static final EnumMap<TimeUnit, String> BASE_TIME_UNIT_STRING_CACHE = Arrays.stream(TimeUnit.values())
         .collect(
@@ -648,12 +652,26 @@ private Meter getOrCreateMeter(@Nullable DistributionStatisticConfig config,
                     }
                     meterMap.put(mappedId, m);
                 }
+                else {
+                    checkAndWarnAboutGaugeDoubleRegistration(m);
+                }
             }
         }
+        else {
+            checkAndWarnAboutGaugeDoubleRegistration(m);
+        }
 
         return m;
     }
 
+    private void checkAndWarnAboutGaugeDoubleRegistration(Meter meter) {
+        if (meter instanceof Gauge) {
+            gaugeDoubleRegistrationLogger.log(() -> String.format(
+                    "This Gauge has been already registered (%s), the Gauge registration will be ignored.",
+                    meter.getId()));
+        }
+    }
+
     private boolean accept(Meter.Id id) {
         for (MeterFilter filter : filters) {
             MeterFilterReply reply = filter.accept(id);