Add support for mapping hints

Author: felixbarny

x-pack/plugin/otel-data/src/main/java/org/elasticsearch/xpack/oteldata/otlp/datapoint/DataPoint.java

@@ -73,10 +73,11 @@ public interface DataPoint {
     /**
      * Builds the metric value for the data point and writes it to the provided XContentBuilder.
      *
+     * @param mappingHints hints for building the metric value
      * @param builder the XContentBuilder to write the metric value to
      * @throws IOException if an I/O error occurs while writing to the builder
      */
-    void buildMetricValue(XContentBuilder builder) throws IOException;
+    void buildMetricValue(MappingHints mappingHints, XContentBuilder builder) throws IOException;
 
     /**
      * Returns the dynamic template name for the data point based on its type and value.
@@ -131,7 +132,7 @@ public String getMetricName() {
         }
 
         @Override
-        public void buildMetricValue(XContentBuilder builder) throws IOException {
+        public void buildMetricValue(MappingHints mappingHints, XContentBuilder builder) throws IOException {
             switch (dataPoint.getValueCase()) {
                 case AS_DOUBLE -> builder.value(dataPoint.getAsDouble());
                 case AS_INT -> builder.value(dataPoint.getAsInt());
@@ -198,16 +199,18 @@ public String getMetricName() {
         }
 
         @Override
-        public void buildMetricValue(XContentBuilder builder) throws IOException {
+        public void buildMetricValue(MappingHints mappingHints, XContentBuilder builder) throws IOException {
             // TODO: Add support for quantiles
-            builder.startObject();
-            builder.field("sum", dataPoint.getSum());
-            builder.field("value_count", dataPoint.getCount());
-            builder.endObject();
+            buildAggregateMetricDouble(builder, dataPoint.getSum(), dataPoint.getCount());
         }
 
         @Override
-        public String getDynamicTemplate() {
+        public long getDocCount() {
+            return dataPoint.getCount();
+        }
+
+        @Override
+        public String getDynamicTemplate(MappingHints mappingHints) {
             return "summary";
         }
 
@@ -216,4 +219,11 @@ public boolean isValid(Set<String> errors) {
             return true;
         }
     }
+
+    private static void buildAggregateMetricDouble(XContentBuilder builder, double sum, long valueCount) throws IOException {
+        builder.startObject();
+        builder.field("sum", sum);
+        builder.field("value_count", valueCount);
+        builder.endObject();
+    }
 }

x-pack/plugin/otel-data/src/main/java/org/elasticsearch/xpack/oteldata/otlp/docbuilder/MappingHints.java

@@ -28,10 +28,10 @@
  */
 public record MappingHints(boolean aggregateMetricDouble, boolean docCount) {
     public static final String MAPPING_HINTS = "elasticsearch.mapping.hints";
+    public static final String AGGREGATE_METRIC_DOUBLE = "aggregate_metric_double";
+    public static final String DOC_COUNT = "_doc_count";
 
     private static final MappingHints EMPTY = new MappingHints(false, false);
-    private static final String AGGREGATE_METRIC_DOUBLE = "aggregate_metric_double";
-    private static final String DOC_COUNT = "_doc_count";
 
     public static MappingHints fromAttributes(List<KeyValue> attributes) {
         boolean aggregateMetricDouble = false;

x-pack/plugin/otel-data/src/main/java/org/elasticsearch/xpack/oteldata/otlp/docbuilder/MetricDocumentBuilder.java

@@ -7,13 +7,11 @@
 
 package org.elasticsearch.xpack.oteldata.otlp.docbuilder;
 
+import com.google.protobuf.ByteString;
 import io.opentelemetry.proto.common.v1.AnyValue;
 import io.opentelemetry.proto.common.v1.InstrumentationScope;
 import io.opentelemetry.proto.common.v1.KeyValue;
 import io.opentelemetry.proto.resource.v1.Resource;
-
-import com.google.protobuf.ByteString;
-
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.xcontent.XContentBuilder;
 import org.elasticsearch.xpack.oteldata.otlp.datapoint.DataPoint;
@@ -51,17 +49,25 @@ public HashMap<String, String> buildMetricDocument(XContentBuilder builder, Data
         buildDataPointAttributes(builder, dataPointGroup.dataPointAttributes(), dataPointGroup.unit());
         builder.field("_metric_names_hash", dataPointGroup.getMetricNamesHash());
 
+        long docCount = 0;
         builder.startObject("metrics");
         for (int i = 0, dataPointsSize = dataPoints.size(); i < dataPointsSize; i++) {
             DataPoint dataPoint = dataPoints.get(i);
             builder.field(dataPoint.getMetricName());
-            dataPoint.buildMetricValue(builder);
-            String dynamicTemplate = dataPoint.getDynamicTemplate(MappingHints.empty());
+            MappingHints mappingHints = MappingHints.fromAttributes(dataPoint.getAttributes());
+            dataPoint.buildMetricValue(mappingHints, builder);
+            String dynamicTemplate = dataPoint.getDynamicTemplate(mappingHints);
             if (dynamicTemplate != null) {
                 dynamicTemplates.put("metrics." + dataPoint.getMetricName(), dynamicTemplate);
             }
+            if (mappingHints.docCount()) {
+                docCount = dataPoint.getDocCount();
+            }
         }
         builder.endObject();
+        if (docCount > 0) {
+            builder.field("_doc_count", docCount);
+        }
         builder.endObject();
         return dynamicTemplates;
     }

x-pack/plugin/otel-data/src/test/java/org/elasticsearch/xpack/oteldata/otlp/OtlpUtils.java

@@ -23,6 +23,8 @@
 import io.opentelemetry.proto.metrics.v1.SummaryDataPoint;
 import io.opentelemetry.proto.resource.v1.Resource;
 
+import org.elasticsearch.xpack.oteldata.otlp.docbuilder.MappingHints;
+
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -40,6 +42,10 @@ public static KeyValue keyValue(String key, String value) {
         return KeyValue.newBuilder().setKey(key).setValue(AnyValue.newBuilder().setStringValue(value).build()).build();
     }
 
+    public static List<KeyValue> mappingHints(String... mappingHints) {
+        return List.of(keyValue(MappingHints.MAPPING_HINTS, mappingHints));
+    }
+
     public static KeyValue keyValue(String key, String... values) {
         return KeyValue.newBuilder()
             .setKey(key)

x-pack/plugin/otel-data/src/test/java/org/elasticsearch/xpack/oteldata/otlp/docbuilder/MetricDocumentBuilderTests.java

@@ -40,6 +40,7 @@
 import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.createSumMetric;
 import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.createSummaryMetric;
 import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.keyValue;
+import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.mappingHints;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.hasEntry;
 import static org.hamcrest.Matchers.is;
@@ -203,6 +204,7 @@ public void testSummary() throws Exception {
             .setStartTimeUnixNano(startTimestamp)
             .setCount(1)
             .setSum(42.0)
+            .addAllAttributes(mappingHints(MappingHints.DOC_COUNT))
             .build();
         Metric metric = createSummaryMetric("summary", "", List.of());
         List<DataPoint> dataPoints = List.of(new DataPoint.Summary(dataPoint, metric));
@@ -224,6 +226,7 @@ public void testSummary() throws Exception {
         ObjectPath doc = ObjectPath.createFromXContent(JsonXContent.jsonXContent, BytesReference.bytes(builder));
         assertThat(doc.evaluate("metrics.summary.sum"), equalTo(42.0));
         assertThat(doc.evaluate("metrics.summary.value_count"), equalTo(1));
+        assertThat(doc.evaluate("_doc_count"), equalTo(1));
         assertThat(dynamicTemplates, hasEntry("metrics.summary", "summary"));
     }
 }