.

Author: sentrivana

sentry_sdk/integrations/opentelemetry/sampler.py

@@ -50,6 +50,19 @@ def get_parent_sampled(parent_context, trace_id):
     return None
 
 
+def get_parent_sample_rate(parent_context, trace_id):
+    # type: (Optional[SpanContext], int) -> Optional[bool]
+    if parent_context is None:
+        return None
+
+    is_span_context_valid = parent_context is not None and parent_context.is_valid
+
+    if is_span_context_valid and parent_context.trace_id == trace_id:
+        return parent_context.trace_state.get(TRACESTATE_SAMPLE_RATE_KEY)
+
+    return None
+
+
 def _update_sample_rate(sample_rate: float, trace_state: TraceState) -> TraceState:
     if TRACESTATE_SAMPLE_RATE_KEY in trace_state:
         trace_state = trace_state.update(TRACESTATE_SAMPLE_RATE_KEY, str(sample_rate))
@@ -168,22 +181,26 @@ def should_sample(
         # Check if there is a traces_sampler
         # Traces_sampler is responsible to check parent sampled to have full transactions.
         has_traces_sampler = callable(client.options.get("traces_sampler"))
-        inherited_parent_sampled = False
+
+        sample_rate_to_propagate = None
 
         if is_root_span and has_traces_sampler:
             sampling_context = create_sampling_context(
                 name, attributes, parent_span_context, trace_id
             )
             sample_rate = client.options["traces_sampler"](sampling_context)
+            sample_rate_to_propagate = sample_rate
         else:
             # Check if there is a parent with a sampling decision
             parent_sampled = get_parent_sampled(parent_span_context, trace_id)
+            parent_sample_rate = get_parent_sample_rate(parent_span_context, trace_id)
             if parent_sampled is not None:
-                sample_rate = parent_sampled
-                inherited_parent_sampled = True
+                sample_rate = bool(parent_sampled)
+                sample_rate_to_propagate = parent_sample_rate
             else:
                 # Check if there is a traces_sample_rate
                 sample_rate = client.options.get("traces_sample_rate")
+                sample_rate_to_propagate = sample_rate
 
         # If the sample rate is invalid, drop the span
         if not is_valid_sample_rate(sample_rate, source=self.__class__.__name__):
@@ -195,22 +212,20 @@ def should_sample(
         # Down-sample in case of back pressure monitor says so
         if is_root_span and client.monitor:
             sample_rate /= 2**client.monitor.downsample_factor
+            if client.monitor.downsample_factor > 0:
+                sample_rate_to_propagate = sample_rate
 
         # Roll the dice on sample rate
         sample_rate = float(cast("Union[bool, float, int]", sample_rate))
         sampled = random.random() < sample_rate
 
         if sampled:
             return sampled_result(
-                parent_span_context,
-                attributes,
-                sample_rate=sample_rate if not inherited_parent_sampled else None,
+                parent_span_context, attributes, sample_rate=sample_rate_to_propagate
             )
         else:
             return dropped_result(
-                parent_span_context,
-                attributes,
-                sample_rate=sample_rate if not inherited_parent_sampled else None,
+                parent_span_context, attributes, sample_rate=sample_rate_to_propagate
             )
 
     def get_description(self) -> str:

tests/test_dsc.py

@@ -118,7 +118,7 @@ def test_dsc_continuation_of_trace(sentry_init, capture_envelopes):
 
     assert "sample_rate" in envelope_trace_header
     assert type(envelope_trace_header["sample_rate"]) == str
-    assert envelope_trace_header["sample_rate"] == "1.0"
+    assert envelope_trace_header["sample_rate"] == "0.01337"
 
     assert "sampled" in envelope_trace_header
     assert type(envelope_trace_header["sampled"]) == str