feat(otlp-transformer): add is_remote_parent span flags to OTLP exported Spans and SpanLinks

CHANGELOG.md

@@ -14,6 +14,8 @@ For notes on migrating to 2.x / 0.200.x see [the upgrade guide](doc/upgrade-to-2
 
 ### :rocket: Features
 
+* feat(otlp-transformer): add span flags support for isRemote property [#5910](https://github.com/open-telemetry/opentelemetry-js/pull/5910) @nikhilmantri0902
+
 ### :bug: Bug Fixes
 
 ### :books: Documentation

experimental/packages/otlp-transformer/src/trace/internal-types.ts

@@ -97,6 +97,9 @@ export interface ISpan {
 
   /** Span status */
   status: IStatus;
+
+  /** Span flags */
+  flags?: number;
 }
 
 /**
@@ -185,4 +188,7 @@ export interface ILink {
 
   /** Link droppedAttributesCount */
   droppedAttributesCount: number;
+
+  /** Link flags */
+  flags?: number;
 }

experimental/packages/otlp-transformer/src/trace/internal.ts

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import type { Link } from '@opentelemetry/api';
+import type { Link, SpanContext } from '@opentelemetry/api';
 import { Resource } from '@opentelemetry/resources';
 import type { ReadableSpan, TimedEvent } from '@opentelemetry/sdk-trace-base';
 import type { Encoder } from '../common/utils';
@@ -34,6 +34,22 @@ import {
 import { OtlpEncodingOptions } from '../common/internal-types';
 import { getOtlpEncoder } from '../common/utils';
 
+// Span flags constants matching the OTLP specification
+const SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK = 0x100;
+const SPAN_FLAGS_CONTEXT_IS_REMOTE_MASK = 0x200;
+
+/**
+ * Builds span flags based on the parent span context's isRemote property.
+ * This follows the OTLP specification for span flags.
+ */
+function buildSpanFlags(parentSpanContext?: SpanContext): number {
+  let flags = SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK;
+  if (parentSpanContext?.isRemote) {
+    flags |= SPAN_FLAGS_CONTEXT_IS_REMOTE_MASK;
+  }
+  return flags;
+}
+
 export function sdkSpanToOtlpSpan(span: ReadableSpan, encoder: Encoder): ISpan {
   const ctx = span.spanContext();
   const status = span.status;
@@ -61,6 +77,7 @@ export function sdkSpanToOtlpSpan(span: ReadableSpan, encoder: Encoder): ISpan {
     },
     links: span.links.map(link => toOtlpLink(link, encoder)),
     droppedLinksCount: span.droppedLinksCount,
+    flags: buildSpanFlags(span.parentSpanContext),
   };
 }
 
@@ -71,6 +88,7 @@ export function toOtlpLink(link: Link, encoder: Encoder): ILink {
     traceId: encoder.encodeSpanContext(link.context.traceId),
     traceState: link.context.traceState?.serialize(),
     droppedAttributesCount: link.droppedAttributesCount || 0,
+    flags: buildSpanFlags(link.context),
   };
 }
 

experimental/packages/otlp-transformer/test/trace.test.ts

@@ -97,6 +97,7 @@ function createExpectedSpanJson(options: OtlpEncodingOptions) {
                         },
                       },
                     ],
+                    flags: 0x100, // SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK
                   },
                 ],
                 startTimeUnixNano: startTime,
@@ -129,6 +130,7 @@ function createExpectedSpanJson(options: OtlpEncodingOptions) {
                   code: EStatusCode.STATUS_CODE_OK,
                   message: undefined,
                 },
+                flags: 0x100, // SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK
               },
             ],
             schemaUrl: 'http://url.to.schema',
@@ -187,6 +189,7 @@ function createExpectedSpanProtobuf() {
                         },
                       },
                     ],
+                    flags: 0x100, // SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK
                   },
                 ],
                 startTimeUnixNano: startTime,
@@ -218,6 +221,7 @@ function createExpectedSpanProtobuf() {
                 status: {
                   code: EStatusCode.STATUS_CODE_OK,
                 },
+                flags: 0x100, // SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK
               },
             ],
             schemaUrl: 'http://url.to.schema',
@@ -574,4 +578,74 @@ describe('Trace', () => {
       );
     });
   });
+
+  describe('span flags', () => {
+    it('sets flags to 0x100 for local parent span context', () => {
+      const exportRequest = createExportTraceServiceRequest([span], {
+        useHex: true,
+      });
+      assert.ok(exportRequest);
+      const spanFlags = exportRequest.resourceSpans?.[0].scopeSpans[0].spans?.[0].flags;
+      assert.strictEqual(spanFlags, 0x100); // SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK
+    });
+
+    it('sets flags to 0x300 for remote parent span context', () => {
+      // Create a span with a remote parent context
+      const remoteParentSpanContext = {
+        spanId: '0000000000000001',
+        traceId: '00000000000000000000000000000001',
+        traceFlags: TraceFlags.SAMPLED,
+        isRemote: true, // This is the key difference
+      };
+
+      const spanWithRemoteParent = {
+        ...span,
+        parentSpanContext: remoteParentSpanContext,
+      };
+
+      const exportRequest = createExportTraceServiceRequest([spanWithRemoteParent], {
+        useHex: true,
+      });
+      assert.ok(exportRequest);
+      const spanFlags = exportRequest.resourceSpans?.[0].scopeSpans[0].spans?.[0].flags;
+      assert.strictEqual(spanFlags, 0x300); // SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK | SPAN_FLAGS_CONTEXT_IS_REMOTE_MASK
+    });
+
+    it('sets flags to 0x100 for links with local context', () => {
+      const exportRequest = createExportTraceServiceRequest([span], {
+        useHex: true,
+      });
+      assert.ok(exportRequest);
+      const linkFlags = exportRequest.resourceSpans?.[0].scopeSpans[0].spans?.[0].links?.[0].flags;
+      assert.strictEqual(linkFlags, 0x100); // SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK
+    });
+
+    it('sets flags to 0x300 for links with remote context', () => {
+      // Create a span with a remote link context
+      const remoteLinkContext = {
+        spanId: '0000000000000003',
+        traceId: '00000000000000000000000000000002',
+        traceFlags: TraceFlags.SAMPLED,
+        isRemote: true, // This is the key difference
+      };
+
+      const remoteLink = {
+        context: remoteLinkContext,
+        attributes: { 'link-attribute': 'string value' },
+        droppedAttributesCount: 0,
+      };
+
+      const spanWithRemoteLink = {
+        ...span,
+        links: [remoteLink],
+      };
+
+      const exportRequest = createExportTraceServiceRequest([spanWithRemoteLink], {
+        useHex: true,
+      });
+      assert.ok(exportRequest);
+      const linkFlags = exportRequest.resourceSpans?.[0].scopeSpans[0].spans?.[0].links?.[0].flags;
+      assert.strictEqual(linkFlags, 0x300); // SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK | SPAN_FLAGS_CONTEXT_IS_REMOTE_MASK
+    });
+  });
 });