Bug fixes in telemetry (#659)

* flush fix, sync fix in e2e test

Signed-off-by: Sai Shree Pradhan <saishree.pradhan@databricks.com>

* sync fix

Signed-off-by: Sai Shree Pradhan <saishree.pradhan@databricks.com>

---------

Signed-off-by: Sai Shree Pradhan <saishree.pradhan@databricks.com>

Author: saishreeeee

src/databricks/sql/telemetry/telemetry_client.py

@@ -127,6 +127,9 @@ def export_latency_log(self, latency_ms, sql_execution_event, sql_statement_id):
     def close(self):
         pass
 
+    def _flush(self):
+        pass
+
 
 class TelemetryClient(BaseTelemetryClient):
     """

tests/e2e/test_concurrent_telemetry.py

@@ -1,3 +1,4 @@
+from concurrent.futures import wait
 import random
 import threading
 import time
@@ -35,6 +36,7 @@ def telemetry_setup_teardown(self):
             if TelemetryClientFactory._executor:
                 TelemetryClientFactory._executor.shutdown(wait=True)
                 TelemetryClientFactory._executor = None
+            TelemetryClientFactory._stop_flush_thread()
             TelemetryClientFactory._initialized = False
 
     def test_concurrent_queries_sends_telemetry(self):
@@ -47,8 +49,7 @@ def test_concurrent_queries_sends_telemetry(self):
         captured_telemetry = []
         captured_session_ids = []
         captured_statement_ids = []
-        captured_responses = []
-        captured_exceptions = []
+        captured_futures = []
 
         original_send_telemetry = TelemetryClient._send_telemetry
         original_callback = TelemetryClient._telemetry_request_callback
@@ -63,18 +64,9 @@ def callback_wrapper(self_client, future, sent_count):
             Wraps the original callback to capture the server's response
             or any exceptions from the async network call.
             """
-            try:
-                original_callback(self_client, future, sent_count)
-                
-                # Now, capture the result for our assertions
-                response = future.result()
-                response.raise_for_status() # Raise an exception for 4xx/5xx errors
-                telemetry_response = response.json()
-                with capture_lock:
-                    captured_responses.append(telemetry_response)
-            except Exception as e:
-                with capture_lock:
-                    captured_exceptions.append(e)
+            with capture_lock:
+                captured_futures.append(future)
+            original_callback(self_client, future, sent_count)
 
         with patch.object(TelemetryClient, "_send_telemetry", send_telemetry_wrapper), \
              patch.object(TelemetryClient, "_telemetry_request_callback", callback_wrapper):
@@ -101,10 +93,26 @@ def execute_query_worker(thread_id):
             # Run the workers concurrently
             run_in_threads(execute_query_worker, num_threads, pass_index=True)
 
-            if TelemetryClientFactory._executor:
-                TelemetryClientFactory._executor.shutdown(wait=True)
+            timeout_seconds = 60
+            start_time = time.time()
+            expected_event_count = num_threads
+
+            while len(captured_futures) < expected_event_count and time.time() - start_time < timeout_seconds:
+                time.sleep(0.1)
+
+            done, not_done = wait(captured_futures, timeout=timeout_seconds)
+            assert not not_done
+
+            captured_exceptions = []
+            captured_responses = []
+            for future in done:
+                try:
+                    response = future.result()
+                    response.raise_for_status()
+                    captured_responses.append(response.json())
+                except Exception as e:
+                    captured_exceptions.append(e)
 
-            # --- VERIFICATION ---
             assert not captured_exceptions
             assert len(captured_responses) > 0