[sdk-metrics] Pass all tags supplied at measurement to ExemplarReserv…

…oir.Offer methods (#5414)
open-telemetry · Mar 6, 2024 · a7f3400 · a7f3400
1 parent df2abe8
commit a7f3400
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Showing 3 changed files with 82 additions and 27 deletions.
diff --git a/src/OpenTelemetry/Metrics/AggregatorStore.cs b/src/OpenTelemetry/Metrics/AggregatorStore.cs
@@ -959,7 +959,7 @@ private void UpdateLong(long value, ReadOnlySpan<KeyValuePair<string, object?>>
     {
         var index = this.FindMetricAggregatorsDefault(tags);
 
-        this.UpdateLongMetricPoint(index, value, tags: default);
+        this.UpdateLongMetricPoint(index, value, tags);
     }
 
     private void UpdateLongCustomTags(long value, ReadOnlySpan<KeyValuePair<string, object?>> tags)
@@ -1014,7 +1014,7 @@ private void UpdateDouble(double value, ReadOnlySpan<KeyValuePair<string, object
     {
         var index = this.FindMetricAggregatorsDefault(tags);
 
-        this.UpdateDoubleMetricPoint(index, value, tags: default);
+        this.UpdateDoubleMetricPoint(index, value, tags);
     }
 
     private void UpdateDoubleCustomTags(double value, ReadOnlySpan<KeyValuePair<string, object?>> tags)

diff --git a/src/OpenTelemetry/Metrics/Exemplar/Exemplar.cs b/src/OpenTelemetry/Metrics/Exemplar/Exemplar.cs
@@ -131,7 +131,10 @@ internal void Update<T>(in ExemplarMeasurement<T> measurement)
             this.SpanId = default;
         }
 
-        this.StoreRawTags(measurement.Tags);
+        if (this.ViewDefinedTagKeys != null)
+        {
+            this.StoreRawTags(measurement.Tags);
+        }
     }
 
     internal void Reset()

diff --git a/test/OpenTelemetry.Tests/Metrics/MetricExemplarTests.cs b/test/OpenTelemetry.Tests/Metrics/MetricExemplarTests.cs
@@ -689,49 +689,79 @@ public void TestTraceBasedExemplarFilter(bool enableTracing)
         }
     }
 
-    [Fact]
-    public void TestExemplarsFilterTags()
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void TestExemplarsFilterTags(bool enableTagFiltering)
     {
-        DateTime testStartTime = DateTime.UtcNow;
         var exportedItems = new List<Metric>();
 
         using var meter = new Meter($"{Utils.GetCurrentMethodName()}");
+
         var histogram = meter.CreateHistogram<double>("testHistogram");
 
+        TestExemplarReservoir? testExemplarReservoir = null;
+
         using var container = this.BuildMeterProvider(out var meterProvider, builder => builder
             .AddMeter(meter.Name)
             .SetExemplarFilter(ExemplarFilterType.AlwaysOn)
-            .AddView(histogram.Name, new MetricStreamConfiguration() { TagKeys = new string[] { "key1" } })
-            .AddInMemoryExporter(exportedItems, metricReaderOptions =>
-            {
-                metricReaderOptions.TemporalityPreference = MetricReaderTemporalityPreference.Delta;
-            }));
+            .AddView(
+                histogram.Name,
+                new MetricStreamConfiguration()
+                {
+                    TagKeys = enableTagFiltering ? new string[] { "key1" } : null,
+                    ExemplarReservoirFactory = () =>
+                    {
+                        if (testExemplarReservoir != null)
+                        {
+                            throw new InvalidOperationException();
+                        }
+
+                        return testExemplarReservoir = new TestExemplarReservoir();
+                    },
+                })
+            .AddInMemoryExporter(exportedItems));
 
-        var measurementValues = GenerateRandomValues(10, false, null);
-        foreach (var value in measurementValues)
-        {
-            histogram.Record(
-                value.Value,
-                new("key1", "value1"),
-                new("key2", "value1"),
-                new("key3", "value1"));
-        }
+        histogram.Record(
+            0,
+            new("key1", "value1"),
+            new("key2", "value2"),
+            new("key3", "value3"));
+
+        meterProvider.ForceFlush();
+
+        Assert.NotNull(testExemplarReservoir);
+        Assert.NotNull(testExemplarReservoir.MeasurementTags);
+        Assert.Equal(3, testExemplarReservoir.MeasurementTags.Length);
+        Assert.Contains(testExemplarReservoir.MeasurementTags, t => t.Key == "key1" && (string?)t.Value == "value1");
+        Assert.Contains(testExemplarReservoir.MeasurementTags, t => t.Key == "key2" && (string?)t.Value == "value2");
+        Assert.Contains(testExemplarReservoir.MeasurementTags, t => t.Key == "key3" && (string?)t.Value == "value3");
 
-        meterProvider.ForceFlush(MaxTimeToAllowForFlush);
         var metricPoint = GetFirstMetricPoint(exportedItems);
+
         Assert.NotNull(metricPoint);
-        Assert.True(metricPoint.Value.StartTime >= testStartTime);
-        Assert.True(metricPoint.Value.EndTime != default);
+
         var exemplars = GetExemplars(metricPoint.Value);
+
         Assert.NotNull(exemplars);
+
         foreach (var exemplar in exemplars)
         {
-            Assert.NotEqual(0, exemplar.FilteredTags.MaximumCount);
+            if (!enableTagFiltering)
+            {
+                Assert.Equal(0, exemplar.FilteredTags.MaximumCount);
+            }
+            else
+            {
+                Assert.Equal(3, exemplar.FilteredTags.MaximumCount);
 
-            var filteredTags = exemplar.FilteredTags.ToReadOnlyList();
+                var filteredTags = exemplar.FilteredTags.ToReadOnlyList();
 
-            Assert.Contains(new("key2", "value1"), filteredTags);
-            Assert.Contains(new("key3", "value1"), filteredTags);
+                Assert.Equal(2, filteredTags.Count);
+
+                Assert.Contains(new("key2", "value2"), filteredTags);
+                Assert.Contains(new("key3", "value3"), filteredTags);
+            }
         }
     }
 
@@ -791,4 +821,26 @@ private static void ValidateExemplars(
 
         Assert.Equal(measurementValues.Count(), count);
     }
+
+    private sealed class TestExemplarReservoir : FixedSizeExemplarReservoir
+    {
+        public TestExemplarReservoir()
+            : base(1)
+        {
+        }
+
+        public KeyValuePair<string, object?>[]? MeasurementTags { get; private set; }
+
+        public override void Offer(in ExemplarMeasurement<double> measurement)
+        {
+            this.MeasurementTags = measurement.Tags.ToArray();
+
+            this.UpdateExemplar(0, in measurement);
+        }
+
+        public override void Offer(in ExemplarMeasurement<long> measurement)
+        {
+            throw new NotSupportedException();
+        }
+    }
 }