Cancel timer when transaction already finished

Author: antonpirker

sentry_sdk/integrations/wsgi.py

@@ -114,6 +114,7 @@ def __call__(self, environ, start_response):
                         )
 
                     method = environ.get("REQUEST_METHOD", "").upper()
+
                     transaction = None
                     if method in self.http_methods_to_capture:
                         transaction = continue_trace(
@@ -124,6 +125,7 @@ def __call__(self, environ, start_response):
                             origin=self.span_origin,
                         )
 
+                    timer = None
                     if transaction is not None:
                         sentry_sdk.start_transaction(
                             transaction,
@@ -135,6 +137,7 @@ def __call__(self, environ, start_response):
                             args=(current_scope, scope),
                         )
                         timer.start()
+
                     try:
                         response = self.app(
                             environ,
@@ -147,7 +150,7 @@ def __call__(self, environ, start_response):
                     except BaseException:
                         exc_info = sys.exc_info()
                         _capture_exception(exc_info)
-                        finish_running_transaction(current_scope, exc_info)
+                        finish_running_transaction(current_scope, exc_info, timer)
                         reraise(*exc_info)
 
         finally:
@@ -157,6 +160,7 @@ def __call__(self, environ, start_response):
             response=response,
             current_scope=current_scope,
             isolation_scope=scope,
+            timer=timer,
         )
 
 
@@ -271,18 +275,20 @@ class _ScopedResponse:
     - WSGI servers streaming responses interleaved from the same thread
     """
 
-    __slots__ = ("_response", "_current_scope", "_isolation_scope")
+    __slots__ = ("_response", "_current_scope", "_isolation_scope", "_timer")
 
     def __init__(
         self,
         response,  # type: Iterator[bytes]
         current_scope,  # type: sentry_sdk.scope.Scope
         isolation_scope,  # type: sentry_sdk.scope.Scope
+        timer=None,  # type: Optional[Timer]
     ):
         # type: (...) -> None
         self._response = response
         self._current_scope = current_scope
         self._isolation_scope = isolation_scope
+        self._timer = timer
 
     def __iter__(self):
         # type: () -> Iterator[bytes]
@@ -304,14 +310,14 @@ def __iter__(self):
         finally:
             with use_isolation_scope(self._isolation_scope):
                 with use_scope(self._current_scope):
-                    finish_running_transaction()
+                    finish_running_transaction(timer=self._timer)
 
     def close(self):
         # type: () -> None
         with use_isolation_scope(self._isolation_scope):
             with use_scope(self._current_scope):
                 try:
-                    finish_running_transaction()
+                    finish_running_transaction(timer=self._timer)
                     self._response.close()  # type: ignore
                 except AttributeError:
                     pass

sentry_sdk/tracing_utils.py

@@ -37,6 +37,7 @@
     from types import FrameType
 
     from sentry_sdk._types import ExcInfo
+    from threading import Timer
 
 
 SENTRY_TRACE_REGEX = re.compile(
@@ -743,12 +744,15 @@ def get_current_span(scope=None):
     from sentry_sdk.tracing import Span
 
 
-def finish_running_transaction(scope=None, exc_info=None):
-    # type: (Optional[sentry_sdk.Scope], Optional[ExcInfo]) -> None
+def finish_running_transaction(scope=None, exc_info=None, timer=None):
+    # type: (Optional[sentry_sdk.Scope], Optional[ExcInfo], Timer) -> None
     current_scope = scope or sentry_sdk.get_current_scope()
     if current_scope.transaction is not None and hasattr(
         current_scope.transaction, "_context_manager_state"
     ):
+        if timer is not None:
+            timer.cancel()
+
         if exc_info is not None:
             current_scope.transaction.__exit__(*exc_info)
         else:

tests/integrations/wsgi/test_wsgi.py

@@ -537,3 +537,40 @@ def long_running_app(environ, start_response):
         assert (
             transaction_duration <= new_max_duration * 1.2
         )  # we allow 2% margin for processing the request
+
+
+def test_long_running_transaction_timer_canceled(sentry_init, capture_events):
+    # we allow transactions to be 0.5 seconds as a maximum
+    new_max_duration = 0.5
+
+    with mock.patch.object(
+        sentry_sdk.integrations.wsgi,
+        "MAX_TRANSACTION_DURATION_SECONDS",
+        new_max_duration,
+    ):
+        with mock.patch(
+            "sentry_sdk.integrations.wsgi.finish_long_running_transaction"
+        ) as mock_finish:
+
+            def generate_content():
+                # This response will take 0.3 seconds to generate
+                for _ in range(3):
+                    time.sleep(0.1)
+                    yield "ok"
+
+            def long_running_app(environ, start_response):
+                start_response("200 OK", [])
+                return generate_content()
+
+            sentry_init(send_default_pii=True, traces_sample_rate=1.0)
+            app = SentryWsgiMiddleware(long_running_app)
+
+            events = capture_events()
+
+            client = Client(app)
+            response = client.get("/")
+            _ = response.get_data()
+
+            (transaction,) = events
+
+            mock_finish.assert_not_called()