fix(tracing): Fix unsampled/deferred trace propagation in span streaming

sentry_sdk/scope.py

@@ -597,7 +597,7 @@ def get_traceparent(self, *args: "Any", **kwargs: "Any") -> "Optional[str]":
 
         span_streaming = has_span_streaming_enabled(client.options)
         # If we have an active span, return traceparent from there
-        if span_streaming and type(self.streamed_span) is StreamedSpan:
+        if span_streaming and self.streamed_span is not None:
             return self.streamed_span._to_traceparent()
         elif not span_streaming and self.span is not None:
             return self.span._to_traceparent()
@@ -617,7 +617,7 @@ def get_baggage(self, *args: "Any", **kwargs: "Any") -> "Optional[Baggage]":
 
         span_streaming = has_span_streaming_enabled(client.options)
         # If we have an active span, return baggage from there
-        if span_streaming and type(self.streamed_span) is StreamedSpan:
+        if span_streaming and self.streamed_span is not None:
             return self.streamed_span._to_baggage()
         elif not span_streaming and self.span is not None:
             return self.span._to_baggage()
@@ -632,7 +632,7 @@ def get_trace_context(self) -> "Dict[str, Any]":
         if (
             has_tracing_enabled(self.get_client().options)
             and self._span is not None
-            and not isinstance(self._span, (NoOpStreamedSpan, NoOpSpan))
+            and not isinstance(self._span, NoOpSpan)
         ):
             return self._span._get_trace_context()
 
@@ -703,7 +703,7 @@ def iter_trace_propagation_headers(
         if (
             has_tracing_enabled(client.options)
             and span is not None
-            and not isinstance(span, (NoOpStreamedSpan, NoOpSpan))
+            and not isinstance(span, NoOpSpan)
         ):
             for header in span._iter_headers():
                 yield header
@@ -1295,13 +1295,18 @@ def start_streamed_span(
             parent_span = self.streamed_span
 
         # If no eligible parent_span was provided and there is no currently
-        # active span, this is a segment
+        # active span, this is a new segment
         if parent_span is None:
             propagation_context = self.get_active_propagation_context()
 
             if is_ignored_span(name, attributes):
                 return NoOpStreamedSpan(
                     scope=self,
+                    segment=None,
+                    trace_id=propagation_context.trace_id,
+                    parent_span_id=propagation_context.parent_span_id,
+                    parent_sampled=propagation_context.parent_sampled,
+                    baggage=propagation_context.baggage,
                     unsampled_reason="ignored",
                 )
 
@@ -1314,10 +1319,18 @@ def start_streamed_span(
             if sample_rate is not None:
                 self._update_sample_rate(sample_rate)
 
-            if sampled is False:
+            if sampled is False or sampled is None:
                 return NoOpStreamedSpan(
                     scope=self,
+                    segment=None,
+                    trace_id=propagation_context.trace_id,
+                    parent_span_id=propagation_context.parent_span_id,
+                    parent_sampled=propagation_context.parent_sampled,
+                    baggage=propagation_context.baggage,
+                    sampled=sampled,
                     unsampled_reason=outcome,
+                    sample_rand=sample_rand,
+                    sample_rate=sample_rate,
                 )
 
             return StreamedSpan(
@@ -1338,11 +1351,21 @@ def start_streamed_span(
         with new_scope():
             if is_ignored_span(name, attributes):
                 return NoOpStreamedSpan(
+                    segment=parent_span._segment,
+                    trace_id=parent_span.trace_id,
+                    parent_span_id=parent_span.span_id,
+                    parent_sampled=parent_span.sampled,
                     unsampled_reason="ignored",
                 )
 
             if isinstance(parent_span, NoOpStreamedSpan):
-                return NoOpStreamedSpan(unsampled_reason=parent_span._unsampled_reason)
+                return NoOpStreamedSpan(
+                    segment=parent_span._segment,
+                    trace_id=parent_span.trace_id,
+                    parent_span_id=parent_span.span_id,
+                    parent_sampled=parent_span.sampled,
+                    unsampled_reason=parent_span._unsampled_reason,
+                )
 
             return StreamedSpan(
                 name=name,
@@ -1361,7 +1384,7 @@ def _update_sample_rate(self, sample_rate: float) -> None:
         propagation_context = self.get_active_propagation_context()
         baggage = propagation_context.baggage
 
-        if baggage is not None:
+        if baggage is not None and baggage.sentry_items.get("sample_rate"):
             baggage.sentry_items["sample_rate"] = str(sample_rate)
 
     def continue_trace(

sentry_sdk/traces.py

@@ -501,16 +501,16 @@ def _dynamic_sampling_context(self) -> "dict[str, str]":
         return self._segment._get_baggage().dynamic_sampling_context()
 
     def _to_traceparent(self) -> str:
-        if self.sampled is True:
+        if self._segment.sampled is True:
             sampled = "1"
-        elif self.sampled is False:
+        elif self._segment.sampled is False:
             sampled = "0"
         else:
             sampled = None
 
-        traceparent = "%s-%s" % (self.trace_id, self.span_id)
+        traceparent = f"{self.trace_id}-{self.span_id}"
         if sampled is not None:
-            traceparent += "-%s" % (sampled,)
+            traceparent += f"-{sampled}"
 
         return traceparent
 
@@ -610,15 +610,36 @@ def _to_json(self) -> "SpanJSON":
 
 class NoOpStreamedSpan(StreamedSpan):
     __slots__ = (
+        "_sampled",
         "_finished",
         "_unsampled_reason",
     )
 
     def __init__(
         self,
+        segment: "Optional[StreamedSpan]" = None,
+        trace_id: "Optional[str]" = None,
+        parent_span_id: "Optional[str]" = None,
+        parent_sampled: "Optional[bool]" = None,
+        baggage: "Optional[Baggage]" = None,
+        sampled: "Optional[bool]" = False,
         unsampled_reason: "Optional[str]" = None,
         scope: "Optional[sentry_sdk.Scope]" = None,
+        sample_rand: "Optional[float]" = None,
+        sample_rate: "Optional[float]" = None,
     ) -> None:
+        self._span_id: "Optional[str]" = None
+
+        self._sampled = sampled
+        self._segment = segment or self
+
+        self._trace_id: "Optional[str]" = trace_id
+        self._parent_span_id = parent_span_id
+        self._parent_sampled = parent_sampled
+        self._baggage = baggage
+        self._sample_rand = sample_rand
+        self._sample_rate = sample_rate
+
         self._scope = scope  # type: ignore[assignment]
         self._unsampled_reason = unsampled_reason
 
@@ -693,9 +714,6 @@ def set_attributes(self, attributes: "Attributes") -> None:
     def remove_attribute(self, key: str) -> None:
         pass
 
-    def _is_segment(self) -> bool:
-        return self._scope is not None
-
     @property
     def status(self) -> "str":
         return SpanStatus.OK.value
@@ -716,17 +734,9 @@ def name(self, value: str) -> None:
     def active(self) -> bool:
         return True
 
-    @property
-    def span_id(self) -> str:
-        return "0000000000000000"
-
-    @property
-    def trace_id(self) -> str:
-        return "00000000000000000000000000000000"
-
     @property
     def sampled(self) -> "Optional[bool]":
-        return False
+        return self._sampled
 
     @property
     def start_timestamp(self) -> "Optional[datetime]":
@@ -736,6 +746,14 @@ def start_timestamp(self) -> "Optional[datetime]":
     def end_timestamp(self) -> "Optional[datetime]":
         return None
 
+    def _get_trace_context(self) -> "dict[str, Any]":
+        return {
+            "trace_id": self.trace_id,
+            "span_id": self.span_id,
+            "parent_span_id": self._parent_span_id,
+            "dynamic_sampling_context": self._dynamic_sampling_context(),
+        }
+
 
 if TYPE_CHECKING:
 

sentry_sdk/tracing_utils.py

@@ -664,7 +664,7 @@ def _fill_sample_rand(self) -> None:
 
         # Get the sample rate and compute the transformation that will map the random value
         # to the desired range: [0, 1), [0, sample_rate), or [sample_rate, 1).
-        sample_rate = try_convert(float, self.baggage.sentry_items.get("sample_rate"))
+        sample_rate = self._sample_rate()
         lower, upper = _sample_rand_range(self.parent_sampled, sample_rate)
 
         try:
@@ -689,6 +689,13 @@ def _sample_rand(self) -> "Optional[str]":
 
         return self.baggage.sentry_items.get("sample_rand")
 
+    def _sample_rate(self) -> "Optional[float]":
+        """Convenience method to get the sample_rate value from the baggage."""
+        if self.baggage is None:
+            return None
+
+        return try_convert(float, self.baggage.sentry_items.get("sample_rate"))
+
 
 class Baggage:
     """
@@ -857,7 +864,8 @@ def populate_from_segment(cls, segment: "StreamedSpan") -> "Baggage":
         options = client.options or {}
 
         sentry_items["trace_id"] = segment.trace_id
-        sentry_items["sample_rand"] = f"{segment._sample_rand:.6f}"  # noqa: E231
+        if segment._sample_rand is not None:
+            sentry_items["sample_rand"] = f"{segment._sample_rand:.6f}"
 
         if options.get("environment"):
             sentry_items["environment"] = options["environment"]
@@ -873,8 +881,8 @@ def populate_from_segment(cls, segment: "StreamedSpan") -> "Baggage":
         if (
             segment.get_attributes().get("sentry.span.source")
             not in LOW_QUALITY_SEGMENT_SOURCES
-        ) and segment._name:
-            sentry_items["transaction"] = segment._name
+        ) and segment.name:
+            sentry_items["transaction"] = segment.name
 
         if segment._sample_rate is not None:
             sentry_items["sample_rate"] = str(segment._sample_rate)
@@ -1533,23 +1541,23 @@ def _make_sampling_decision(
     name: str,
     attributes: "Optional[Attributes]",
     scope: "sentry_sdk.Scope",
-) -> "tuple[bool, Optional[float], Optional[float], Optional[str]]":
+) -> "tuple[Optional[bool], Optional[float], Optional[float], Optional[str]]":
     """
     Decide whether a span should be sampled.
 
     Returns a tuple with:
-    1. the sampling decision
+    1. the sampling decision (sampled, unsampled, deferred)
     2. the effective sample rate
     3. the sample rand
     4. the reason for not sampling the span, if unsampled
     """
     client = sentry_sdk.get_client()
 
-    if not has_tracing_enabled(client.options):
-        return False, None, None, None
-
     propagation_context = scope.get_active_propagation_context()
 
+    if not has_tracing_enabled(client.options):
+        return propagation_context.parent_sampled, None, None, None
+
     sample_rand = None
     if propagation_context.baggage is not None:
         sample_rand = propagation_context.baggage._sample_rand()
@@ -1575,7 +1583,10 @@ def _make_sampling_decision(
         sample_rate = client.options["traces_sampler"](sampling_context)
     else:
         if propagation_context.parent_sampled is not None:
-            sample_rate = propagation_context.parent_sampled
+            if propagation_context._sample_rate() is not None:
+                sample_rate = propagation_context._sample_rate()
+            else:
+                sample_rate = propagation_context.parent_sampled
         else:
             sample_rate = client.options["traces_sample_rate"]
 
@@ -1585,15 +1596,15 @@ def _make_sampling_decision(
         logger.warning(f"[Tracing] Discarding {name} because of invalid sample rate.")
         return False, None, None, "sample_rate"
 
-    sample_rate = float(sample_rate)
+    sample_rate = float(sample_rate)  # type: ignore[arg-type]
     if not sample_rate:
         if traces_sampler_defined:
             reason = "traces_sampler returned 0 or False"
         else:
             reason = "traces_sample_rate is set to 0"
 
         logger.debug(f"[Tracing] Discarding {name} because {reason}")
-        return False, 0.0, None, "sample_rate"
+        return False, 0.0, sample_rand, "sample_rate"
 
     # Adjust sample rate if we're under backpressure
     sample_rate_before_backpressure = sample_rate

tests/integrations/stdlib/test_httplib.py

@@ -282,9 +282,14 @@ def getresponse(self, *args, **kwargs):
     headers = {
         "sentry-trace": "771a43a4192642f0b136d5159a501700-1234567890abcdef-1",
         "baggage": (
-            "other-vendor-value-1=foo;bar;baz, sentry-trace_id=771a43a4192642f0b136d5159a501700, "
-            "sentry-public_key=49d0f7386ad645858ae85020e393bef3, sentry-sample_rate=0.01337, "
-            "sentry-user_id=Am%C3%A9lie, sentry-sample_rand=0.132521102938283, other-vendor-value-2=foo;bar;"
+            "other-vendor-value-1=foo;bar;baz,"
+            "sentry-trace_id=771a43a4192642f0b136d5159a501700,"
+            "sentry-public_key=49d0f7386ad645858ae85020e393bef3,"
+            "sentry-sample_rate=0.01337,"
+            "sentry-user_id=Am%C3%A9lie,"
+            "sentry-sample_rand=0.000005,"
+            "sentry-sampled=true,"
+            "other-vendor-value-2=foo;bar;"
         ),
     }
 
@@ -309,6 +314,15 @@ def getresponse(self, *args, **kwargs):
             parent_span_id=request_span["span_id"],
             sampled=1,
         )
+
+        expected_outgoing_baggage = (
+            "sentry-trace_id=771a43a4192642f0b136d5159a501700,"
+            "sentry-public_key=49d0f7386ad645858ae85020e393bef3,"
+            "sentry-sample_rate=0.01337,"
+            "sentry-user_id=Am%C3%A9lie,"
+            "sentry-sample_rand=0.000005,"
+            "sentry-sampled=true"
+        )
     else:
         events = capture_events()
         transaction = continue_trace(headers)
@@ -331,16 +345,18 @@ def getresponse(self, *args, **kwargs):
             sampled=1,
         )
 
-    assert request_headers["sentry-trace"] == expected_sentry_trace
-
-    expected_outgoing_baggage = (
-        "sentry-trace_id=771a43a4192642f0b136d5159a501700,"
-        "sentry-public_key=49d0f7386ad645858ae85020e393bef3,"
-        "sentry-sample_rate=1.0,"
-        "sentry-user_id=Am%C3%A9lie,"
-        "sentry-sample_rand=0.132521102938283"
-    )
+        # Note: the sample rate here is actually wrong. It's fixed in the
+        # streaming path
+        expected_outgoing_baggage = (
+            "sentry-trace_id=771a43a4192642f0b136d5159a501700,"
+            "sentry-public_key=49d0f7386ad645858ae85020e393bef3,"
+            "sentry-sample_rate=1.0,"
+            "sentry-user_id=Am%C3%A9lie,"
+            "sentry-sample_rand=0.000005,"
+            "sentry-sampled=true"
+        )
 
+    assert request_headers["sentry-trace"] == expected_sentry_trace
     assert request_headers["baggage"] == expected_outgoing_baggage