propagate lpid if spans are not equal

DataDog · May 9, 2024 · 0e3a0f1 · 0e3a0f1
1 parent 93c11c8
commit 0e3a0f1
Showing 1 changed file with 11 additions and 8 deletions.
diff --git a/lib/datadog/tracing/distributed/propagation.rb b/lib/datadog/tracing/distributed/propagation.rb
@@ -101,17 +101,20 @@ def extract(data)
               # Only parse if it represent the same trace as the successfully extracted one
               next unless tracecontext_digest.trace_id == extracted_trace_digest.trace_id
 
-              tracecontext_digest.trace_distributed_tags |= {}
-              extracted_trace_digest.trace_distributed_tags[Tracing::Metadata::Ext::Distributed::TAG_DD_PARENT_ID] = if tracecontext_digest.span_id == extracted_trace_digest.span_id
-                "%.16x" % tracecontext_digest.span_id
-              else
-                # Preserve the last datadog parent id in `trace_distributed_tags`
-                tracecontext_digest.trace_distributed_tags.fetch(Tracing::Metadata::Ext::Distributed::TAG_DD_PARENT_ID, Tracing::Metadata::Ext::Distributed::DD_PARENT_ID_DEFAULT)
+              distributed_tags = extracted_trace_digest.trace_distributed_tags
+              unless tracecontext_digest.span_id == extracted_trace_digest.span_id
+                distributed_tags = distributed_tags&.dup || {}
+                distributed_tags[Tracing::Metadata::Ext::Distributed::TAG_DD_PARENT_ID] =
+                  tracecontext_digest.trace_distributed_tags.fetch(
+                    Tracing::Metadata::Ext::Distributed::TAG_DD_PARENT_ID,
+                    Tracing::Metadata::Ext::Distributed::DD_PARENT_ID_DEFAULT
+                  )
               end
-              # Preserve the `tracestate`
+              # Preserve the trace state and last datadog span id
               extracted_trace_digest = extracted_trace_digest.merge(
                 trace_state: tracecontext_digest.trace_state,
-                trace_state_unknown_fields: tracecontext_digest.trace_state_unknown_fields
+                trace_state_unknown_fields: tracecontext_digest.trace_state_unknown_fields,
+                trace_distributed_tags: distributed_tags
               )
             end
           rescue => e