[exporter/elasticsearch] Add span event to traces OTel mapping mode

Author: carsonip

.chloggen/elasticsearchexporter_otel-mode-traces-span-events.yaml

@@ -0,0 +1,29 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: elasticsearchexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add span event support to traces OTel mapping mode
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [34831]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+  Span events are now supported in OTel mapping mode.
+  They will be routed to `logs-${data_stream.dataset}-${data_stream.namespace}` if `traces_dynamic_index::enabled` is `true`.
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

exporter/elasticsearchexporter/README.md

@@ -135,7 +135,7 @@ This can be customised through the following settings:
 
 - `traces_dynamic_index` (optional): uses resource, scope, or span attributes to dynamically construct index name.
   - `enabled`(default=false): Enable/Disable dynamic index for trace spans. If `data_stream.dataset` or `data_stream.namespace` exist in attributes (precedence: span attribute > scope attribute > resource attribute), they will be used to dynamically construct index name in the form `traces-${data_stream.dataset}-${data_stream.namespace}`. Otherwise, if
-    `elasticsearch.index.prefix` or `elasticsearch.index.suffix` exist in attributes (precedence: resource attribute > scope attribute > span attribute), they will be used to dynamically construct index name in the form `${elasticsearch.index.prefix}${traces_index}${elasticsearch.index.suffix}`. Otherwise, the index name falls back to `traces-generic-default`, and `traces_index` config will be ignored. Except for prefix/suffix attribute presence, the resulting docs will contain the corresponding `data_stream.*` fields.
+    `elasticsearch.index.prefix` or `elasticsearch.index.suffix` exist in attributes (precedence: resource attribute > scope attribute > span attribute), they will be used to dynamically construct index name in the form `${elasticsearch.index.prefix}${traces_index}${elasticsearch.index.suffix}`. Otherwise, the index name falls back to `traces-generic-default`, and `traces_index` config will be ignored. Except for prefix/suffix attribute presence, the resulting docs will contain the corresponding `data_stream.*` fields. There is an exception for span events under OTel mapping mode (`mapping::mode: otel`), where span event attributes instead of span attributes are considered, and `data_stream.type` is always `logs` instead of `traces` such that documents are routed to `logs-${data_stream.dataset}-${data_stream.namespace}`.
 
 - `logstash_format` (optional): Logstash format compatibility. Logs, metrics and traces can be written into an index in Logstash format.
   - `enabled`(default=false):  Enable/disable Logstash format compatibility. When `logstash_format.enabled` is `true`, the index name is composed using `(logs|metrics|traces)_index` or `(logs|metrics|traces)_dynamic_index` as prefix and the date as suffix,
@@ -155,8 +155,10 @@ behaviours, which may be configured through the following settings:
     - `none`: Use original fields and event structure from the OTLP event.
     - `ecs`: Try to map fields to [Elastic Common Schema (ECS)][ECS]
     - `otel`: Elastic's preferred "OTel-native" mapping mode. Uses original fields and event structure from the OTLP event.
-          :warning: This mode's behavior is unstable, it is currently is experimental and undergoing changes.
-          There's a special treatment for the following attributes: `data_stream.type`, `data_stream.dataset`, `data_stream.namespace`. Instead of serializing these values under the `*attributes.*` namespace, they're put at the root of the document, to conform with the conventions of the data stream naming scheme that maps these as `constant_keyword` fields.
+      - :warning: This mode's behavior is unstable, it is currently is experimental and undergoing changes. 
+      - There's a special treatment for the following attributes: `data_stream.type`, `data_stream.dataset`, `data_stream.namespace`. Instead of serializing these values under the `*attributes.*` namespace, they're put at the root of the document, to conform with the conventions of the data stream naming scheme that maps these as `constant_keyword` fields.
+      - `data_stream.dataset` will always be appended with `.otel`. It is recommended to use with `*_dynamic_index.enabled: true` to route documents to data stream `${data_stream.type}-${data_stream.dataset}-${data_stream.namespace}`.
+      - Span events are stored in separate documents. They will be routed with `data_stream.type` set to `logs` if `traces_dynamic_index::enabled` is `true`.
 
     - `raw`: Omit the `Attributes.` string prefixed to field names for log and 
              span attributes as well as omit the `Events.` string prefixed to

exporter/elasticsearchexporter/data_stream_router.go

@@ -11,7 +11,7 @@ import (
 	"go.opentelemetry.io/collector/pdata/ptrace"
 )
 
-func routeWithDefaults(defaultDSType, defaultDSDataset, defaultDSNamespace string) func(
+func routeWithDefaults(defaultDSType, defaultDSDataset, defaultDSNamespace string) func( // nolint:unparam
 	pcommon.Map,
 	pcommon.Map,
 	pcommon.Map,
@@ -91,3 +91,17 @@ func routeSpan(
 	route := routeWithDefaults(defaultDataStreamTypeTraces, defaultDataStreamDataset, defaultDataStreamNamespace)
 	return route(span.Attributes(), scope.Attributes(), resource.Attributes(), fIndex, otel)
 }
+
+// routeSpanEvent returns the name of the index to send the span event to according to data stream routing attributes.
+// This function may mutate record attributes.
+func routeSpanEvent(
+	spanEvent ptrace.SpanEvent,
+	scope pcommon.InstrumentationScope,
+	resource pcommon.Resource,
+	fIndex string,
+	otel bool,
+) string {
+	// span events are sent to logs-*, not traces-*
+	route := routeWithDefaults(defaultDataStreamTypeLogs, defaultDataStreamDataset, defaultDataStreamNamespace)
+	return route(spanEvent.Attributes(), scope.Attributes(), resource.Attributes(), fIndex, otel)
+}

exporter/elasticsearchexporter/exporter.go

@@ -361,6 +361,12 @@ func (e *elasticsearchExporter) pushTraceData(
 					}
 					errs = append(errs, err)
 				}
+				for ii := 0; ii < span.Events().Len(); ii++ {
+					spanEvent := span.Events().At(ii)
+					if err := e.pushSpanEvent(ctx, resource, il.SchemaUrl(), span, spanEvent, scope, scopeSpan.SchemaUrl(), session); err != nil {
+						errs = append(errs, err)
+					}
+				}
 			}
 		}
 	}
@@ -402,3 +408,37 @@ func (e *elasticsearchExporter) pushTraceRecord(
 	}
 	return bulkIndexerSession.Add(ctx, fIndex, bytes.NewReader(document), nil)
 }
+
+func (e *elasticsearchExporter) pushSpanEvent(
+	ctx context.Context,
+	resource pcommon.Resource,
+	resourceSchemaURL string,
+	span ptrace.Span,
+	spanEvent ptrace.SpanEvent,
+	scope pcommon.InstrumentationScope,
+	scopeSchemaURL string,
+	bulkIndexerSession bulkIndexerSession,
+) error {
+	fIndex := e.index
+	if e.dynamicIndex {
+		fIndex = routeSpanEvent(spanEvent, scope, resource, fIndex, e.otel)
+	}
+
+	if e.logstashFormat.Enabled {
+		formattedIndex, err := generateIndexWithLogstashFormat(fIndex, &e.logstashFormat, time.Now())
+		if err != nil {
+			return err
+		}
+		fIndex = formattedIndex
+	}
+
+	document := e.model.encodeSpanEvent(resource, resourceSchemaURL, span, spanEvent, scope, scopeSchemaURL)
+	if document == nil {
+		return nil
+	}
+	docBytes, err := e.model.encodeDocument(*document)
+	if err != nil {
+		return err
+	}
+	return bulkIndexerSession.Add(ctx, fIndex, bytes.NewReader(docBytes), nil)
+}

exporter/elasticsearchexporter/exporter_test.go

@@ -1060,6 +1060,11 @@ func TestExporterTraces(t *testing.T) {
 		span.SetStartTimestamp(pcommon.NewTimestampFromTime(time.Unix(3600, 0)))
 		span.SetEndTimestamp(pcommon.NewTimestampFromTime(time.Unix(7200, 0)))
 
+		event := span.Events().AppendEmpty()
+		event.SetName("exception")
+		event.Attributes().PutStr("event.attr.foo", "event.attr.bar")
+		event.SetDroppedAttributesCount(1)
+
 		scopeAttr := span.Attributes()
 		fillResourceAttributeMap(scopeAttr, map[string]string{
 			"attr.foo": "attr.bar",
@@ -1082,13 +1087,17 @@ func TestExporterTraces(t *testing.T) {
 
 		mustSendTraces(t, exporter, traces)
 
-		rec.WaitItems(1)
+		rec.WaitItems(2)
 
 		expected := []itemRequest{
 			{
 				Action:   []byte(`{"create":{"_index":"traces-generic.otel-default"}}`),
 				Document: []byte(`{"@timestamp":"1970-01-01T01:00:00.000000000Z","attributes":{"attr.foo":"attr.bar"},"data_stream":{"dataset":"generic.otel","namespace":"default","type":"traces"},"dropped_attributes_count":2,"dropped_events_count":3,"dropped_links_count":4,"duration":3600000000000,"kind":"Unspecified","links":[{"attributes":{"link.attr.foo":"link.attr.bar"},"dropped_attributes_count":11,"span_id":"","trace_id":"","trace_state":"bar"}],"name":"name","resource":{"attributes":{"resource.foo":"resource.bar"},"dropped_attributes_count":0},"scope":{"dropped_attributes_count":0},"status":{"code":"Unset"},"trace_state":"foo"}`),
 			},
+			{
+				Action:   []byte(`{"create":{"_index":"logs-generic.otel-default"}}`),
+				Document: []byte(`{"@timestamp":"1970-01-01T00:00:00.000000000Z","attributes":{"event.attr.foo":"event.attr.bar","event.name":"exception"},"data_stream":{"dataset":"generic.otel","namespace":"default","type":"logs"},"dropped_attributes_count":1,"resource":{"attributes":{"resource.foo":"resource.bar"},"dropped_attributes_count":0},"scope":{"dropped_attributes_count":0}}`),
+			},
 		}
 
 		assertItemsEqual(t, expected, rec.Items(), false)

exporter/elasticsearchexporter/model.go

@@ -66,6 +66,7 @@ var resourceAttrsToPreserve = map[string]bool{
 type mappingModel interface {
 	encodeLog(pcommon.Resource, string, plog.LogRecord, pcommon.InstrumentationScope, string) ([]byte, error)
 	encodeSpan(pcommon.Resource, string, ptrace.Span, pcommon.InstrumentationScope, string) ([]byte, error)
+	encodeSpanEvent(resource pcommon.Resource, resourceSchemaURL string, span ptrace.Span, spanEvent ptrace.SpanEvent, scope pcommon.InstrumentationScope, scopeSchemaURL string) *objmodel.Document
 	upsertMetricDataPointValue(map[uint32]objmodel.Document, pcommon.Resource, string, pcommon.InstrumentationScope, string, pmetric.Metric, dataPoint, pcommon.Value) error
 	encodeDocument(objmodel.Document) ([]byte, error)
 }
@@ -463,7 +464,9 @@ func (m *encodeModel) encodeScopeOTelMode(document *objmodel.Document, scope pco
 }
 
 func (m *encodeModel) encodeAttributesOTelMode(document *objmodel.Document, attributeMap pcommon.Map) {
-	attributeMap.RemoveIf(func(key string, val pcommon.Value) bool {
+	attrsCopy := pcommon.NewMap() // Copy to avoid mutating original map
+	attributeMap.CopyTo(attrsCopy)
+	attrsCopy.RemoveIf(func(key string, val pcommon.Value) bool {
 		switch key {
 		case dataStreamType, dataStreamDataset, dataStreamNamespace:
 			// At this point the data_stream attributes are expected to be in the record attributes,
@@ -474,7 +477,7 @@ func (m *encodeModel) encodeAttributesOTelMode(document *objmodel.Document, attr
 		}
 		return false
 	})
-	document.AddAttributes("attributes", attributeMap)
+	document.AddAttributes("attributes", attrsCopy)
 }
 
 func (m *encodeModel) encodeSpan(resource pcommon.Resource, resourceSchemaURL string, span ptrace.Span, scope pcommon.InstrumentationScope, scopeSchemaURL string) ([]byte, error) {
@@ -529,8 +532,6 @@ func (m *encodeModel) encodeSpanOTelMode(resource pcommon.Resource, resourceSche
 	m.encodeResourceOTelMode(&document, resource, resourceSchemaURL)
 	m.encodeScopeOTelMode(&document, scope, scopeSchemaURL)
 
-	// TODO: add span events to log data streams
-
 	return document
 }
 
@@ -554,6 +555,26 @@ func (m *encodeModel) encodeSpanDefaultMode(resource pcommon.Resource, span ptra
 	return document
 }
 
+func (m *encodeModel) encodeSpanEvent(resource pcommon.Resource, resourceSchemaURL string, span ptrace.Span, spanEvent ptrace.SpanEvent, scope pcommon.InstrumentationScope, scopeSchemaURL string) *objmodel.Document {
+	if m.mode != MappingOTel {
+		// Currently span events are stored separately only in OTel mapping mode.
+		// In other modes, they are stored within the span document.
+		return nil
+	}
+	var document objmodel.Document
+	document.AddTimestamp("@timestamp", spanEvent.Timestamp())
+	document.AddString("attributes.event.name", spanEvent.Name())
+	document.AddSpanID("span_id", span.SpanID())
+	document.AddTraceID("trace_id", span.TraceID())
+	document.AddInt("dropped_attributes_count", int64(spanEvent.DroppedAttributesCount()))
+
+	m.encodeAttributesOTelMode(&document, spanEvent.Attributes())
+	m.encodeResourceOTelMode(&document, resource, resourceSchemaURL)
+	m.encodeScopeOTelMode(&document, scope, scopeSchemaURL)
+
+	return &document
+}
+
 func (m *encodeModel) encodeAttributes(document *objmodel.Document, attributes pcommon.Map) {
 	key := "Attributes"
 	if m.mode == MappingRaw {