feat: Add is_remote flag in exporter for spans and span links (#3153)

nikhilmantri0902 · web-flow · commit 159135c62b09 · 2025-09-17T19:17:32.000+05:30
diff --git a/opentelemetry-otlp/src/exporter/http/mod.rs b/opentelemetry-otlp/src/exporter/http/mod.rs
@@ -1047,6 +1047,7 @@ mod tests {
             SpanData {
                 span_context,
                 parent_span_id: SpanId::from(0),
+                parent_span_is_remote: false,
                 span_kind: SpanKind::Internal,
                 name: Cow::Borrowed("test_span"),
                 start_time: SystemTime::UNIX_EPOCH,
diff --git a/opentelemetry-proto/CHANGELOG.md b/opentelemetry-proto/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## vNext
 
+- **Feature**: Add span flags support for `isRemote` property in OTLP trace transformation ([#3153](https://github.com/open-telemetry/opentelemetry-rust/pull/3153))
+- Updated span and link transformations to properly set flags field (0x100 for local, 0x300 for remote)
+
 ## 0.30.1
 
 Released 2025-Sep-11
diff --git a/opentelemetry-proto/src/transform/trace.rs b/opentelemetry-proto/src/transform/trace.rs
@@ -1,3 +1,16 @@
+#[cfg(feature = "gen-tonic-messages")]
+/// Builds span flags based on the parent span's remote property.
+/// This follows the OTLP specification for span flags.
+pub(crate) fn build_span_flags(parent_span_is_remote: bool, base_flags: u32) -> u32 {
+    use crate::proto::tonic::trace::v1::SpanFlags;
+    let mut flags = base_flags;
+    flags |= SpanFlags::ContextHasIsRemoteMask as u32;
+    if parent_span_is_remote {
+        flags |= SpanFlags::ContextIsRemoteMask as u32;
+    }
+    flags
+}
+
 #[cfg(feature = "gen-tonic-messages")]
 pub mod tonic {
     use crate::proto::tonic::resource::v1::Resource;
@@ -41,7 +54,10 @@ pub mod tonic {
                 trace_state: link.span_context.trace_state().header(),
                 attributes: Attributes::from(link.attributes).0,
                 dropped_attributes_count: link.dropped_attributes_count,
-                flags: link.span_context.trace_flags().to_u8() as u32,
+                flags: super::build_span_flags(
+                    link.span_context.is_remote(),
+                    link.span_context.trace_flags().to_u8() as u32,
+                ),
             }
         }
     }
@@ -59,7 +75,10 @@ pub mod tonic {
                         vec![]
                     }
                 },
-                flags: source_span.span_context.trace_flags().to_u8() as u32,
+                flags: super::build_span_flags(
+                    source_span.parent_span_is_remote,
+                    source_span.span_context.trace_flags().to_u8() as u32,
+                ),
                 name: source_span.name.into_owned(),
                 kind: span_kind as i32,
                 start_time_unix_nano: to_nanos(source_span.start_time),
@@ -118,7 +137,10 @@ pub mod tonic {
                                 vec![]
                             }
                         },
-                        flags: source_span.span_context.trace_flags().to_u8() as u32,
+                        flags: super::build_span_flags(
+                            source_span.parent_span_is_remote,
+                            source_span.span_context.trace_flags().to_u8() as u32,
+                        ),
                         name: source_span.name.into_owned(),
                         kind: span_kind as i32,
                         start_time_unix_nano: to_nanos(source_span.start_time),
@@ -191,6 +213,101 @@ pub mod tonic {
     }
 }
 
+#[cfg(all(test, feature = "gen-tonic-messages"))]
+mod span_flags_tests {
+    use crate::proto::tonic::trace::v1::{Span, SpanFlags};
+    use opentelemetry::trace::{SpanContext, SpanId, TraceFlags, TraceId, TraceState};
+    use opentelemetry::InstrumentationScope;
+    use opentelemetry_sdk::trace::SpanData;
+    use std::borrow::Cow;
+
+    #[test]
+    fn test_build_span_flags_local_parent() {
+        let flags = super::build_span_flags(false, 0); // is_remote = false
+        assert_eq!(flags, SpanFlags::ContextHasIsRemoteMask as u32); // 0x100
+    }
+
+    #[test]
+    fn test_build_span_flags_remote_parent() {
+        let flags = super::build_span_flags(true, 0); // is_remote = true
+        assert_eq!(
+            flags,
+            (SpanFlags::ContextHasIsRemoteMask as u32) | (SpanFlags::ContextIsRemoteMask as u32)
+        ); // 0x300
+    }
+
+    #[test]
+    fn test_build_span_flags_no_parent() {
+        let flags = super::build_span_flags(false, 0); // no parent = false
+        assert_eq!(flags, SpanFlags::ContextHasIsRemoteMask as u32); // 0x100
+    }
+
+    #[test]
+    fn test_build_span_flags_preserves_base_flags() {
+        let flags = super::build_span_flags(false, 0x01); // SAMPLED flag, local parent
+        assert_eq!(flags, 0x01 | (SpanFlags::ContextHasIsRemoteMask as u32)); // 0x101
+    }
+
+    #[test]
+    fn test_span_transformation_with_flags() {
+        let span_data = SpanData {
+            span_context: SpanContext::new(
+                TraceId::from(789),
+                SpanId::from(101112),
+                TraceFlags::default(),
+                false,
+                TraceState::default(),
+            ),
+            parent_span_id: SpanId::from(456),
+            parent_span_is_remote: false,
+            span_kind: opentelemetry::trace::SpanKind::Internal,
+            name: Cow::Borrowed("test_span"),
+            start_time: std::time::SystemTime::now(),
+            end_time: std::time::SystemTime::now(),
+            attributes: vec![],
+            dropped_attributes_count: 0,
+            events: opentelemetry_sdk::trace::SpanEvents::default(),
+            links: opentelemetry_sdk::trace::SpanLinks::default(),
+            status: opentelemetry::trace::Status::Unset,
+            instrumentation_scope: InstrumentationScope::builder("test").build(),
+        };
+
+        let otlp_span: Span = span_data.into();
+        assert_eq!(otlp_span.flags, SpanFlags::ContextHasIsRemoteMask as u32); // 0x100
+    }
+
+    #[test]
+    fn test_span_transformation_with_remote_parent() {
+        let span_data = SpanData {
+            span_context: SpanContext::new(
+                TraceId::from(789),
+                SpanId::from(101112),
+                TraceFlags::default(),
+                false,
+                TraceState::default(),
+            ),
+            parent_span_id: SpanId::from(456),
+            parent_span_is_remote: true,
+            span_kind: opentelemetry::trace::SpanKind::Internal,
+            name: Cow::Borrowed("test_span"),
+            start_time: std::time::SystemTime::now(),
+            end_time: std::time::SystemTime::now(),
+            attributes: vec![],
+            dropped_attributes_count: 0,
+            events: opentelemetry_sdk::trace::SpanEvents::default(),
+            links: opentelemetry_sdk::trace::SpanLinks::default(),
+            status: opentelemetry::trace::Status::Unset,
+            instrumentation_scope: InstrumentationScope::builder("test").build(),
+        };
+
+        let otlp_span: Span = span_data.into();
+        assert_eq!(
+            otlp_span.flags,
+            (SpanFlags::ContextHasIsRemoteMask as u32) | (SpanFlags::ContextIsRemoteMask as u32)
+        ); // 0x300
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::tonic::common::v1::any_value::Value;
@@ -219,6 +336,7 @@ mod tests {
         SpanData {
             span_context,
             parent_span_id: SpanId::from(0),
+            parent_span_is_remote: false,
             span_kind: SpanKind::Internal,
             name: Cow::Borrowed("test_span"),
             start_time: now(),
diff --git a/opentelemetry-sdk/CHANGELOG.md b/opentelemetry-sdk/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## vNext
 
+- **Feature**: Add span flags support for `isRemote` property in OTLP exporter ([#3153](https://github.com/open-telemetry/opentelemetry-rust/pull/3153))
+- Updated span and link transformations to properly set flags field (0x100 for local, 0x300 for remote)
+
 - TODO: Placeholder for Span processor related things
   - *Fix* SpanProcessor::on_start is no longer called on non recording spans
 - **Fix**: Restore true parallel exports in the async-native `BatchSpanProcessor` by honoring `OTEL_BSP_MAX_CONCURRENT_EXPORTS` ([#2959](https://github.com/open-telemetry/opentelemetry-rust/pull/3028)). A regression in [#2685](https://github.com/open-telemetry/opentelemetry-rust/pull/2685) inadvertently awaited the `export()` future directly in `opentelemetry-sdk/src/trace/span_processor_with_async_runtime.rs` instead of spawning it on the runtime, forcing all exports to run sequentially.
diff --git a/opentelemetry-sdk/benches/batch_span_processor.rs b/opentelemetry-sdk/benches/batch_span_processor.rs
@@ -22,6 +22,7 @@ fn get_span_data() -> Vec<SpanData> {
                 TraceState::default(),
             ),
             parent_span_id: SpanId::from(12),
+            parent_span_is_remote: false,
             span_kind: SpanKind::Client,
             name: Default::default(),
             start_time: now(),
diff --git a/opentelemetry-sdk/src/testing/trace/span_exporters.rs b/opentelemetry-sdk/src/testing/trace/span_exporters.rs
@@ -21,6 +21,7 @@ pub fn new_test_export_span_data() -> SpanData {
             TraceState::default(),
         ),
         parent_span_id: SpanId::INVALID,
+        parent_span_is_remote: false,
         span_kind: SpanKind::Internal,
         name: "opentelemetry".into(),
         start_time: opentelemetry::time::now(),
diff --git a/opentelemetry-sdk/src/trace/export.rs b/opentelemetry-sdk/src/trace/export.rs
@@ -82,6 +82,8 @@ pub struct SpanData {
     pub span_context: SpanContext,
     /// Span parent id
     pub parent_span_id: SpanId,
+    /// Parent span is remote flag (for span flags)
+    pub parent_span_is_remote: bool,
     /// Span kind
     pub span_kind: SpanKind,
     /// Span name
diff --git a/opentelemetry-sdk/src/trace/span.rs b/opentelemetry-sdk/src/trace/span.rs
@@ -27,6 +27,8 @@ pub struct Span {
 pub(crate) struct SpanData {
     /// Span parent id
     pub(crate) parent_span_id: SpanId,
+    /// Parent span is remote flag (for span flags)
+    pub(crate) parent_span_is_remote: bool,
     /// Span kind
     pub(crate) span_kind: SpanKind,
     /// Span name
@@ -254,6 +256,7 @@ fn build_export_data(
     crate::trace::SpanData {
         span_context,
         parent_span_id: data.parent_span_id,
+        parent_span_is_remote: data.parent_span_is_remote,
         span_kind: data.span_kind,
         name: data.name,
         start_time: data.start_time,
@@ -286,6 +289,7 @@ mod tests {
         let tracer = provider.tracer("opentelemetry");
         let data = SpanData {
             parent_span_id: SpanId::from(0),
+            parent_span_is_remote: false,
             span_kind: trace::SpanKind::Internal,
             name: "opentelemetry".into(),
             start_time: opentelemetry::time::now(),
diff --git a/opentelemetry-sdk/src/trace/span_processor.rs b/opentelemetry-sdk/src/trace/span_processor.rs
@@ -968,6 +968,7 @@ mod tests {
         let unsampled = SpanData {
             span_context: SpanContext::empty_context(),
             parent_span_id: SpanId::INVALID,
+            parent_span_is_remote: false,
             span_kind: SpanKind::Internal,
             name: "opentelemetry".into(),
             start_time: opentelemetry::time::now(),
@@ -1129,6 +1130,7 @@ mod tests {
         SpanData {
             span_context: SpanContext::empty_context(),
             parent_span_id: SpanId::INVALID,
+            parent_span_is_remote: false,
             span_kind: SpanKind::Internal,
             name: name.to_string().into(),
             start_time: opentelemetry::time::now(),
@@ -1256,6 +1258,7 @@ mod tests {
         let exporter_shared = exporter.exported_spans.clone(); // Shared access to verify exported spans
         let config = BatchConfigBuilder::default()
             .with_max_queue_size(2) // Small queue size to test span dropping
+            .with_max_export_batch_size(512) // Explicitly set to avoid env var override
             .with_scheduled_delay(Duration::from_secs(5))
             .build();
         let processor = BatchSpanProcessor::new(exporter, config);
@@ -1270,7 +1273,7 @@ mod tests {
         processor.on_end(span3.clone()); // This span exceeds the queue size
 
         // Wait for the scheduled delay to expire
-        std::thread::sleep(Duration::from_secs(3));
+        std::thread::sleep(Duration::from_secs(6));
 
         let exported_spans = exporter_shared.lock().unwrap();
 
diff --git a/opentelemetry-sdk/src/trace/tracer.rs b/opentelemetry-sdk/src/trace/tracer.rs
@@ -137,6 +137,7 @@ impl SdkTracer {
             sc,
             Some(SpanData {
                 parent_span_id: psc.span_id(),
+                parent_span_is_remote: psc.is_valid() && psc.is_remote(),
                 span_kind: builder.span_kind.take().unwrap_or(SpanKind::Internal),
                 name,
                 start_time,
diff --git a/opentelemetry-zipkin/src/exporter/model/span.rs b/opentelemetry-zipkin/src/exporter/model/span.rs
@@ -154,6 +154,7 @@ mod tests {
                     Default::default(),
                 ),
                 parent_span_id: SpanId::from(1),
+                parent_span_is_remote: false,
                 span_kind: SpanKind::Client,
                 name: "".into(),
                 start_time: now(),
