bugfix: RandomIdGenerator can generate invalid Span/Trace Ids

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+- Fix RandomIdGenerator can generate invalid Span/Trace Ids
+  ([#3949](https://github.com/open-telemetry/opentelemetry-python/pull/3949))
+
 ## Version 1.25.0/0.46b0 (2024-05-30)
 
 - Fix class BoundedAttributes to have RLock rather than Lock

opentelemetry-sdk/src/opentelemetry/sdk/trace/id_generator.py

@@ -15,6 +15,8 @@
 import abc
 import random
 
+from opentelemetry.trace.span import INVALID_SPAN_ID, INVALID_TRACE_ID
+
 
 class IdGenerator(abc.ABC):
     @abc.abstractmethod
@@ -46,7 +48,13 @@ class RandomIdGenerator(IdGenerator):
     """
 
     def generate_span_id(self) -> int:
-        return random.getrandbits(64)
+        span_id = random.getrandbits(64)
+        while span_id == INVALID_SPAN_ID:
+            span_id = random.getrandbits(64)
+        return span_id
 
     def generate_trace_id(self) -> int:
-        return random.getrandbits(128)
+        trace_id = random.getrandbits(128)
+        while trace_id == INVALID_TRACE_ID:
+            trace_id = random.getrandbits(128)
+        return trace_id

opentelemetry-sdk/tests/trace/test_trace.py

@@ -62,6 +62,7 @@
     StatusCode,
     get_tracer,
     set_tracer_provider,
+    span,
 )
 
 
@@ -2061,3 +2062,28 @@ def test_tracer_provider_init_default(self, resource_patch, sample_patch):
         sample_patch.assert_called_once()
         self.assertIsNotNone(tracer_provider._span_limits)
         self.assertIsNotNone(tracer_provider._atexit_handler)
+
+
+class TestRandomIdGenerator(unittest.TestCase):
+    _TRACE_ID_MAX_VALUE = 2 ** 128 - 1
+    _SPAN_ID_MAX_VALUE = 2 ** 64 - 1
+
+    @patch('random.getrandbits', side_effect=[span.INVALID_SPAN_ID, 0x00000000DEADBEF0])
+    def test_generate_span_id_avoids_invalid(self, mock_getrandbits):
+        generator = RandomIdGenerator()
+        span_id = generator.generate_span_id()
+
+        self.assertNotEqual(span_id, span.INVALID_SPAN_ID)
+        self.assertGreater(span_id, span.INVALID_SPAN_ID)
+        self.assertLessEqual(span_id, self._SPAN_ID_MAX_VALUE)
+        self.assertEqual(mock_getrandbits.call_count, 2)  # Ensure exactly two calls
+
+    @patch('random.getrandbits', side_effect=[span.INVALID_TRACE_ID, 0x000000000000000000000000DEADBEEF])
+    def test_generate_trace_id_avoids_invalid(self, mock_getrandbits):
+        generator = RandomIdGenerator()
+        trace_id = generator.generate_trace_id()
+
+        self.assertNotEqual(trace_id, span.INVALID_TRACE_ID)
+        self.assertGreater(trace_id, span.INVALID_TRACE_ID)
+        self.assertLessEqual(trace_id, self._TRACE_ID_MAX_VALUE)
+        self.assertEqual(mock_getrandbits.call_count, 2)  # Ensure exactly two calls