improvements

Author: sentrivana

sentry_sdk/traces.py

@@ -487,16 +487,19 @@ def _end(self, end_timestamp: "Optional[Union[float, datetime]]" = None) -> None
         if self._finished:
             return
 
-        client = sentry_sdk.get_client()
-        if client.is_active() and client.transport:
-            logger.debug("Discarding span because sampled = False")
-            client.transport.record_lost_event(
-                reason=self._unsampled_reason or "sample_rate",
-                data_category="span",
-                quantity=1,
-            )
+        if self._unsampled_reason is not None:
+            client = sentry_sdk.get_client()
+            if client.is_active() and client.transport:
+                logger.debug(
+                    f"Discarding span because sampled=False (reason: {self._unsampled_reason})"
+                )
+                client.transport.record_lost_event(
+                    reason=self._unsampled_reason,
+                    data_category="span",
+                    quantity=1,
+                )
 
-        if self._scope:
+        if self._scope and hasattr(self, "_previous_span_on_scope"):
             with capture_internal_exceptions():
                 old_span = self._previous_span_on_scope
                 del self._previous_span_on_scope

sentry_sdk/tracing_utils.py

@@ -1409,21 +1409,21 @@ def _make_sampling_decision(
     if sample_rand is None:
         sample_rand = _generate_sample_rand(propagation_context.trace_id)
 
-    sampling_context = {
-        "name": name,
-        "trace_id": propagation_context.trace_id,
-        "parent_span_id": propagation_context.parent_span_id,
-        "parent_sampled": propagation_context.parent_sampled,
-        "attributes": attributes or {},
-    }
-
     # If there's a traces_sampler, use that; otherwise use traces_sample_rate
     traces_sampler_defined = callable(client.options.get("traces_sampler"))
     if traces_sampler_defined:
+        sampling_context = {
+            "name": name,
+            "trace_id": propagation_context.trace_id,
+            "parent_span_id": propagation_context.parent_span_id,
+            "parent_sampled": propagation_context.parent_sampled,
+            "attributes": dict(attributes) if attributes else {},
+        }
+
         sample_rate = client.options["traces_sampler"](sampling_context)
     else:
-        if sampling_context["parent_sampled"] is not None:
-            sample_rate = sampling_context["parent_sampled"]
+        if propagation_context.parent_sampled is not None:
+            sample_rate = propagation_context.parent_sampled
         else:
             sample_rate = client.options["traces_sample_rate"]
 
@@ -1434,26 +1434,22 @@ def _make_sampling_decision(
         return False, None, None, None
 
     sample_rate = float(sample_rate)
-
-    # Adjust sample rate if we're under backpressure
-    if client.monitor:
-        sample_rate /= 2**client.monitor.downsample_factor
-
-    outcome: "Optional[str]" = None
-
     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}")
-        if client.monitor and client.monitor.downsample_factor > 0:
-            outcome = "backpressure"
-        else:
-            outcome = "sample_rate"
+        return False, 0.0, None, "sample_rate"
+
+    # Adjust sample rate if we're under backpressure
+    if client.monitor:
+        sample_rate /= 2**client.monitor.downsample_factor
 
-        return False, 0.0, None, outcome
+        if not sample_rate:
+            logger.debug(f"[Tracing] Discarding {name} because backpressure")
+            return False, 0.0, None, "backpressure"
 
     sampled = sample_rand < sample_rate