Make PrometheusMeterRegistry continue silently on meters with same na…

…me and different tags (#2400) See gh-2068 Fixes gh-2399
micrometer-metrics · Jan 21, 2021 · b31d0e8 · b31d0e8
1 parent 40b6c71
commit b31d0e8
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Showing 2 changed files with 14 additions and 3 deletions.
diff --git a/...r-registry-prometheus/src/main/java/io/micrometer/prometheus/PrometheusMeterRegistry.java b/...r-registry-prometheus/src/main/java/io/micrometer/prometheus/PrometheusMeterRegistry.java
@@ -420,7 +420,7 @@ private void applyToCollector(Meter.Id id, Consumer<MicrometerCollector> consume
                     " set of tag keys. There is already an existing meter named '" + id.getName() + "' containing tag keys [" +
                     String.join(", ", collectorMap.get(getConventionName(id)).getTagKeys()) + "]. The meter you are attempting to register" +
                     " has keys [" + getConventionTags(id).stream().map(Tag::getKey).collect(joining(", ")) + "].");
-            return null;
+            return existingCollector;
         });
     }
 

diff --git a/...gistry-prometheus/src/test/java/io/micrometer/prometheus/PrometheusMeterRegistryTest.java b/...gistry-prometheus/src/test/java/io/micrometer/prometheus/PrometheusMeterRegistryTest.java
@@ -63,6 +63,14 @@ void before() {
         registry.config().namingConvention(new PrometheusDurationNamingConvention());
     }
 
+    @Test
+    void metersWithSameNameAndDifferentTagsContinueSilently() {
+        String meterName = "my.counter";
+        registry.counter(meterName, "k1", "v1");
+        registry.counter(meterName, "k2", "v2");
+        registry.counter(meterName, "k3", "v3");
+    }
+
     @Test
     void meterRegistrationFailedListenerCalledOnSameNameDifferentTags() throws InterruptedException {
         CountDownLatch failedLatch = new CountDownLatch(1);
@@ -75,10 +83,13 @@ void meterRegistrationFailedListenerCalledOnSameNameDifferentTags() throws Inter
         assertThatThrownBy(() -> registry
                 .throwExceptionOnRegistrationFailure()
                 .counter("my.counter", "k1", "v1")
-        ).isInstanceOf(IllegalArgumentException.class);
+        )
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageStartingWith("Prometheus requires that all meters with the same name have the same set of tag keys.");
 
         assertThatThrownBy(() -> registry.counter("my.counter", "k2", "v2"))
-                .isInstanceOf(IllegalArgumentException.class);
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageStartingWith("Prometheus requires that all meters with the same name have the same set of tag keys.");
     }
 
     @Test