fix

Author: sentrivana

sentry_sdk/integrations/opentelemetry/sampler.py

@@ -195,7 +195,22 @@ def should_sample(
             sample_rand = parent_sample_rand
         else:
             lower, upper = _sample_rand_range(parent_sampled, parent_sample_rate)
-            sample_rand = _generate_sample_rand(trace_id, (lower, upper))
+
+            try:
+                sample_rand = _generate_sample_rand(trace_id, (lower, upper))
+            except ValueError:
+                # ValueError is raised if the interval is invalid, i.e. lower >= upper.
+                # lower >= upper might happen if the incoming trace's sampled flag
+                # and sample_rate are inconsistent, e.g. sample_rate=0.0 but sampled=True.
+                # We cannot generate a sensible sample_rand value in this case.
+                logger.debug(
+                    f"Could not backfill sample_rand, since parent_sampled={parent_sampled} "
+                    f"and sample_rate={sample_rate}."
+                )
+                logger.warning(
+                    f"[Tracing] Discarding {name} because of invalid sample rate/sampled."
+                )
+                return dropped_result(parent_span_context, attributes)
 
         # Explicit sampled value provided at start_span
         custom_sampled = cast(

tests/test_dsc.py

@@ -176,10 +176,10 @@ def my_traces_sampler(sampling_context):
     }
 
     # We continue the incoming trace and start a new transaction
-    monkeypatch.setattr(random, "random", lambda: 0.125)
-    with sentry_sdk.continue_trace(incoming_http_headers):
-        with sentry_sdk.start_span(name="foo"):
-            pass
+    with mock.patch("sentry_sdk.tracing_utils.Random.uniform", return_value=0.125):
+        with sentry_sdk.continue_trace(incoming_http_headers):
+            with sentry_sdk.start_span(name="foo"):
+                pass
 
     assert len(envelopes) == 1