OTLP: add support for summaries

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

@@ -10,6 +10,7 @@
 import io.opentelemetry.proto.common.v1.KeyValue;
 import io.opentelemetry.proto.metrics.v1.Metric;
 import io.opentelemetry.proto.metrics.v1.NumberDataPoint;
+import io.opentelemetry.proto.metrics.v1.SummaryDataPoint;
 
 import org.elasticsearch.xcontent.XContentBuilder;
 import org.elasticsearch.xpack.oteldata.otlp.docbuilder.MappingHints;
@@ -72,10 +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.
@@ -130,7 +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());
@@ -168,4 +170,60 @@ public boolean isValid(Set<String> errors) {
             return true;
         }
     }
+
+    record Summary(SummaryDataPoint dataPoint, Metric metric) implements DataPoint {
+
+        @Override
+        public long getTimestampUnixNano() {
+            return dataPoint.getTimeUnixNano();
+        }
+
+        @Override
+        public List<KeyValue> getAttributes() {
+            return dataPoint.getAttributesList();
+        }
+
+        @Override
+        public long getStartTimestampUnixNano() {
+            return dataPoint.getStartTimeUnixNano();
+        }
+
+        @Override
+        public String getUnit() {
+            return metric.getUnit();
+        }
+
+        @Override
+        public String getMetricName() {
+            return metric.getName();
+        }
+
+        @Override
+        public void buildMetricValue(MappingHints mappingHints, XContentBuilder builder) throws IOException {
+            // TODO: Add support for quantiles
+            buildAggregateMetricDouble(builder, dataPoint.getSum(), dataPoint.getCount());
+        }
+
+        @Override
+        public long getDocCount() {
+            return dataPoint.getCount();
+        }
+
+        @Override
+        public String getDynamicTemplate(MappingHints mappingHints) {
+            return "summary";
+        }
+
+        @Override
+        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/datapoint/DataPointGroupingContext.java

@@ -77,8 +77,7 @@ public void groupDataPoints(ExportMetricsServiceRequest exportMetricsServiceRequ
                             ignoredDataPointMessages.add("Histogram is not supported yet. Dropping " + metric.getName());
                             break;
                         case SUMMARY:
-                            ignoredDataPoints += metric.getSummary().getDataPointsList().size();
-                            ignoredDataPointMessages.add("Summary is not supported yet. Dropping " + metric.getName());
+                            scopeGroup.addDataPoints(metric, metric.getSummary().getDataPointsList(), DataPoint.Summary::new);
                             break;
                         default:
                             ignoredDataPoints++;

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

@@ -27,10 +27,12 @@
  *                              In these cases, the behavior is undefined but does not lead to data loss.
  */
 public record MappingHints(boolean aggregateMetricDouble, boolean docCount) {
-    private static final String MAPPING_HINTS = "elasticsearch.mapping.hints";
+
+    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

@@ -55,17 +55,25 @@ public HashMap<String, String> buildMetricDocument(XContentBuilder builder, Data
         buildDataPointAttributes(builder, dataPointGroup.dataPointAttributes(), dataPointGroup.unit());
         builder.field("_metric_names_hash", dataPointGroup.getMetricNamesHash(hasher));
 
+        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

@@ -19,8 +19,12 @@
 import io.opentelemetry.proto.metrics.v1.ResourceMetrics;
 import io.opentelemetry.proto.metrics.v1.ScopeMetrics;
 import io.opentelemetry.proto.metrics.v1.Sum;
+import io.opentelemetry.proto.metrics.v1.Summary;
+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;
@@ -38,6 +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)
@@ -105,6 +113,14 @@ public static Metric createSumMetric(
             .build();
     }
 
+    public static Metric createSummaryMetric(String name, String unit, List<SummaryDataPoint> dataPoints) {
+        return Metric.newBuilder()
+            .setName(name)
+            .setUnit(unit)
+            .setSummary(Summary.newBuilder().addAllDataPoints(dataPoints).build())
+            .build();
+    }
+
     public static NumberDataPoint createDoubleDataPoint(long timestamp) {
         return createDoubleDataPoint(timestamp, timestamp, List.of());
     }
@@ -131,6 +147,16 @@ public static NumberDataPoint createLongDataPoint(long timeUnixNano, long startT
             .build();
     }
 
+    public static SummaryDataPoint createSummaryDataPoint(long timestamp, List<KeyValue> attributes) {
+        return SummaryDataPoint.newBuilder()
+            .setTimeUnixNano(timestamp)
+            .setStartTimeUnixNano(timestamp)
+            .addAllAttributes(attributes)
+            .setCount(randomLong())
+            .setSum(randomDouble())
+            .build();
+    }
+
     public static ExportMetricsServiceRequest createMetricsRequest(List<Metric> metrics) {
 
         List<ResourceMetrics> resourceMetrics = new ArrayList<>();

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

@@ -25,6 +25,8 @@
 import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.createResourceMetrics;
 import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.createScopeMetrics;
 import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.createSumMetric;
+import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.createSummaryDataPoint;
+import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.createSummaryMetric;
 import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.keyValue;
 import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.hamcrest.Matchers.containsString;
@@ -46,11 +48,12 @@ public void testGroupingSameGroup() throws Exception {
                     List.of(createLongDataPoint(nowUnixNanos)),
                     true,
                     AGGREGATION_TEMPORALITY_CUMULATIVE
-                )
+                ),
+                createSummaryMetric("summary", "", List.of(createSummaryDataPoint(nowUnixNanos, List.of())))
             )
         );
         context.groupDataPoints(metricsRequest);
-        assertEquals(3, context.totalDataPoints());
+        assertEquals(4, context.totalDataPoints());
         assertEquals(0, context.getIgnoredDataPoints());
         assertEquals("", context.getIgnoredDataPointsMessage());
 

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

@@ -10,6 +10,7 @@
 import io.opentelemetry.proto.common.v1.InstrumentationScope;
 import io.opentelemetry.proto.common.v1.KeyValue;
 import io.opentelemetry.proto.metrics.v1.AggregationTemporality;
+import io.opentelemetry.proto.metrics.v1.SummaryDataPoint;
 import io.opentelemetry.proto.resource.v1.Resource;
 
 import com.google.protobuf.ByteString;
@@ -37,7 +38,9 @@
 import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.createGaugeMetric;
 import static org.elasticsearch.xpack.oteldata.otlp.OtlpUtils.createLongDataPoint;
 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;
@@ -197,4 +200,40 @@ public void testEmptyFields() throws IOException {
         assertThat(doc.evaluate("unit"), is(nullValue()));
     }
 
+    public void testSummary() throws Exception {
+        Resource resource = Resource.newBuilder().build();
+        InstrumentationScope scope = InstrumentationScope.newBuilder().build();
+
+        DataPointGroupingContext.DataPointGroup dataPointGroup = new DataPointGroupingContext.DataPointGroup(
+            resource,
+            null,
+            scope,
+            null,
+            List.of(),
+            "",
+            TargetIndex.defaultMetrics()
+        );
+        dataPointGroup.addDataPoint(
+            Set.of(),
+            new DataPoint.Summary(
+                SummaryDataPoint.newBuilder()
+                    .setTimeUnixNano(timestamp)
+                    .setStartTimeUnixNano(startTimestamp)
+                    .setCount(1)
+                    .setSum(42.0)
+                    .addAllAttributes(mappingHints(MappingHints.DOC_COUNT))
+                    .build(),
+                createSummaryMetric("summary", "", List.of())
+            )
+        );
+
+        XContentBuilder builder = XContentFactory.contentBuilder(XContentType.JSON);
+        HashMap<String, String> dynamicTemplates = documentBuilder.buildMetricDocument(builder, dataPointGroup);
+
+        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"));
+    }
 }