Improve Resource Detector timeout messaging

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+- Improve Resource Detector timeout messaging
+  ([#3645](https://github.com/open-telemetry/opentelemetry-python/pull/3645))
+
 ## Version 1.22.0/0.43b0 (2023-12-15)
 
 - Prometheus exporter sanitize info metric ([#3572](https://github.com/open-telemetry/opentelemetry-python/pull/3572))

opentelemetry-sdk/src/opentelemetry/sdk/resources/__init__.py

@@ -390,6 +390,14 @@ def get_aggregated_resources(
             detected_resource: Resource = _EMPTY_RESOURCE
             try:
                 detected_resource = future.result(timeout=timeout)
+            except concurrent.futures.TimeoutError as ex:
+                if detector.raise_on_error:
+                    raise ex
+                logger.warning(
+                    "Detector %s took longer than %s seconds, skipping",
+                    detector,
+                    timeout,
+                )
             # pylint: disable=broad-except
             except Exception as ex:
                 if detector.raise_on_error:

opentelemetry-sdk/tests/resources/test_resources.py

@@ -15,6 +15,7 @@
 import sys
 import unittest
 import uuid
+from concurrent.futures import TimeoutError
 from logging import ERROR, WARNING
 from os import environ
 from unittest.mock import Mock, patch
@@ -420,6 +421,23 @@ def test_resource_detector_raise_error(self):
             Exception, get_aggregated_resources, [resource_detector]
         )
 
+    @patch("opentelemetry.sdk.resources.logger")
+    def test_resource_detector_timeout(self, mock_logger):
+        resource_detector = Mock(spec=ResourceDetector)
+        resource_detector.detect.side_effect = TimeoutError()
+        resource_detector.raise_on_error = False
+        self.assertEqual(
+            get_aggregated_resources([resource_detector]),
+            _DEFAULT_RESOURCE.merge(
+                Resource({SERVICE_NAME: "unknown_service"}, "")
+            ),
+        )
+        mock_logger.warning.assert_called_with(
+            "Detector %s took longer than %s seconds, skipping",
+            resource_detector,
+            5,
+        )
+
     @patch.dict(
         environ,
         {"OTEL_RESOURCE_ATTRIBUTES": "key1=env_value1,key2=env_value2"},