Fix flaky test that tests lots of threads calling emit. Make sure tests shutdown the batch exporter. (open-telemetry#4600)

* Initital commit to imporve shutdown behavior.

* Remove print statements and changes from shutdown branch

* Remove unused imports/deps

* fix lint issue

---------

Co-authored-by: Riccardo Magliocchetti <[email protected]>

Author: DylanRussell

opentelemetry-sdk/test-requirements.txt

@@ -14,4 +14,4 @@ zipp==3.19.2
 -e tests/opentelemetry-test-utils
 -e opentelemetry-api
 -e opentelemetry-semantic-conventions
--e opentelemetry-sdk
+-e opentelemetry-sdk

opentelemetry-sdk/tests/logs/test_export.py

@@ -17,6 +17,7 @@
 import os
 import time
 import unittest
+from concurrent.futures import ThreadPoolExecutor
 from sys import version_info
 from unittest.mock import Mock, patch
 
@@ -331,9 +332,12 @@ def test_simple_log_record_processor_different_msg_types_with_formatter(
         self.assertEqual(expected, emitted)
 
 
+# Many more test cases for the BatchLogRecordProcessor exist under
+# opentelemetry-sdk/tests/shared_internal/test_batch_processor.py.
+# Important: make sure to call .shutdown() on the BatchLogRecordProcessor
+# before the end of the test, otherwise the worker thread will continue
+# to run after the end of the test.
 class TestBatchLogRecordProcessor(unittest.TestCase):
-    # Many more test cases for the BatchLogRecordProcessor exist under
-    # opentelemetry-sdk/tests/shared_internal/test_batch_processor.py.
     def test_emit_call_log_record(self):
         exporter = InMemoryLogExporter()
         log_record_processor = Mock(wraps=BatchLogRecordProcessor(exporter))
@@ -346,6 +350,34 @@ def test_emit_call_log_record(self):
 
         logger.error("error")
         self.assertEqual(log_record_processor.emit.call_count, 1)
+        log_record_processor.shutdown()
+
+    def test_with_multiple_threads(self):  # pylint: disable=no-self-use
+        exporter = InMemoryLogExporter()
+        batch_processor = BatchLogRecordProcessor(
+            exporter,
+            max_queue_size=3000,
+            max_export_batch_size=50,
+            schedule_delay_millis=30000,
+            export_timeout_millis=500,
+        )
+
+        def bulk_emit(num_emit):
+            for _ in range(num_emit):
+                batch_processor.emit(EMPTY_LOG)
+
+        total_expected_logs = 0
+        with ThreadPoolExecutor(max_workers=69) as executor:
+            for num_logs_to_emit in range(1, 70):
+                executor.submit(bulk_emit, num_logs_to_emit)
+                total_expected_logs += num_logs_to_emit
+
+            executor.shutdown()
+
+        batch_processor.shutdown()
+        # Wait a bit for logs to flush.
+        time.sleep(2)
+        assert len(exporter.get_finished_logs()) == total_expected_logs
 
     @mark.skipif(
         version_info < (3, 10),
@@ -404,6 +436,7 @@ def test_args(self):
         self.assertEqual(
             log_record_processor._batch_processor._export_timeout_millis, 15000
         )
+        log_record_processor.shutdown()
 
     @patch.dict(
         "os.environ",
@@ -432,6 +465,7 @@ def test_env_vars(self):
         self.assertEqual(
             log_record_processor._batch_processor._export_timeout_millis, 15000
         )
+        log_record_processor.shutdown()
 
     def test_args_defaults(self):
         exporter = InMemoryLogExporter()
@@ -451,6 +485,7 @@ def test_args_defaults(self):
         self.assertEqual(
             log_record_processor._batch_processor._export_timeout_millis, 30000
         )
+        log_record_processor.shutdown()
 
     @patch.dict(
         "os.environ",
@@ -481,6 +516,7 @@ def test_args_env_var_value_error(self):
         self.assertEqual(
             log_record_processor._batch_processor._export_timeout_millis, 30000
         )
+        log_record_processor.shutdown()
 
     def test_args_none_defaults(self):
         exporter = InMemoryLogExporter()
@@ -506,6 +542,7 @@ def test_args_none_defaults(self):
         self.assertEqual(
             log_record_processor._batch_processor._export_timeout_millis, 30000
         )
+        log_record_processor.shutdown()
 
     def test_validation_negative_max_queue_size(self):
         exporter = InMemoryLogExporter()

opentelemetry-sdk/tests/shared_internal/test_batch_processor.py

@@ -19,13 +19,10 @@
 import time
 import unittest
 import weakref
-from concurrent.futures import ThreadPoolExecutor
 from platform import system
-from sys import version_info
 from unittest.mock import Mock
 
 import pytest
-from pytest import mark
 
 from opentelemetry.sdk._logs import (
     LogData,
@@ -53,6 +50,8 @@
 
 
 # BatchLogRecodProcessor/BatchSpanProcessor initialize and use BatchProcessor.
+# Important: make sure to call .shutdown() before the end of the test,
+# otherwise the worker thread will continue to run after the end of the test.
 @pytest.mark.parametrize(
     "batch_processor_class,telemetry",
     [(BatchLogRecordProcessor, EMPTY_LOG), (BatchSpanProcessor, BASIC_SPAN)],
@@ -80,6 +79,7 @@ def test_telemetry_exported_once_batch_size_reached(
         after_export = time.time_ns()
         # Shows the worker's 30 second sleep was interrupted within a second.
         assert after_export - before_export < 1e9
+        batch_processor.shutdown()
 
     # pylint: disable=no-self-use
     def test_telemetry_exported_once_schedule_delay_reached(
@@ -96,6 +96,7 @@ def test_telemetry_exported_once_schedule_delay_reached(
         batch_processor._batch_processor.emit(telemetry)
         time.sleep(0.2)
         exporter.export.assert_called_once_with([telemetry])
+        batch_processor.shutdown()
 
     def test_telemetry_flushed_before_shutdown_and_dropped_after_shutdown(
         self, batch_processor_class, telemetry
@@ -136,33 +137,7 @@ def test_force_flush_flushes_telemetry(
             batch_processor._batch_processor.emit(telemetry)
         batch_processor.force_flush()
         exporter.export.assert_called_once_with([telemetry for _ in range(10)])
-
-    @mark.skipif(
-        system() == "Windows" or version_info < (3, 9),
-        reason="This test randomly fails on windows and python 3.8.",
-    )
-    def test_with_multiple_threads(self, batch_processor_class, telemetry):
-        exporter = Mock()
-        batch_processor = batch_processor_class(
-            exporter,
-            max_queue_size=3000,
-            max_export_batch_size=1000,
-            schedule_delay_millis=30000,
-            export_timeout_millis=500,
-        )
-
-        def bulk_emit_and_flush(num_emit):
-            for _ in range(num_emit):
-                batch_processor._batch_processor.emit(telemetry)
-            batch_processor.force_flush()
-
-        with ThreadPoolExecutor(max_workers=69) as executor:
-            for idx in range(69):
-                executor.submit(bulk_emit_and_flush, idx + 1)
-
-            executor.shutdown()
-        # 69 calls to force flush.
-        assert exporter.export.call_count == 69
+        batch_processor.shutdown()
 
     @unittest.skipUnless(
         hasattr(os, "fork"),
@@ -202,6 +177,7 @@ def child(conn):
         batch_processor.force_flush()
         # Single export for the telemetry we emitted at the start of the test.
         assert exporter.export.call_count == 1
+        batch_processor.shutdown()
 
     def test_record_processor_is_garbage_collected(
         self, batch_processor_class, telemetry

opentelemetry-sdk/tests/trace/export/test_export.py

@@ -144,9 +144,12 @@ def test_simple_span_processor_not_sampled(self):
         self.assertListEqual([], spans_names_list)
 
 
+# Many more test cases for the BatchSpanProcessor exist under
+# opentelemetry-sdk/tests/shared_internal/test_batch_processor.py.
+# Important: make sure to call .shutdown() on the BatchSpanProcessor
+# before the end of the test, otherwise the worker thread will continue
+# to run after the end of the test.
 class TestBatchSpanProcessor(unittest.TestCase):
-    # Many more test cases for the BatchSpanProcessor exist under
-    # opentelemetry-sdk/tests/shared_internal/test_batch_processor.py.
     @mock.patch.dict(
         "os.environ",
         {
@@ -173,6 +176,7 @@ def test_args_env_var(self):
         self.assertEqual(
             batch_span_processor._batch_processor._export_timeout_millis, 4
         )
+        batch_span_processor.shutdown()
 
     def test_args_env_var_defaults(self):
         batch_span_processor = export.BatchSpanProcessor(
@@ -191,6 +195,7 @@ def test_args_env_var_defaults(self):
         self.assertEqual(
             batch_span_processor._batch_processor._export_timeout_millis, 30000
         )
+        batch_span_processor.shutdown()
 
     @mock.patch.dict(
         "os.environ",
@@ -220,6 +225,7 @@ def test_args_env_var_value_error(self):
         self.assertEqual(
             batch_span_processor._batch_processor._export_timeout_millis, 30000
         )
+        batch_span_processor.shutdown()
 
     def test_on_start_accepts_parent_context(self):
         # pylint: disable=no-self-use