Capture logs of test_recovery test

Otherwise they end up overrunning Twisted’s AMP protocol message size and raising a `TooLong` error.

Author: anoadragon453

tests/storage/databases/main/test_events_worker.py

@@ -449,28 +449,31 @@ def test_failure(self) -> None:
 
     def test_recovery(self) -> None:
         """Test that event fetchers recover after a database outage."""
-        with self._outage():
-            # Kick off a bunch of event fetches but do not pump the reactor
-            event_deferreds = []
-            for event_id in self.event_ids:
-                d = ensureDeferred(self.store.get_event(event_id))
-                # Prevent the failures from being logged as unhandled by adding
-                # a no-op errback.
-                d.addErrback(lambda failure: failure)
-                event_deferreds.append(d)
-
-            # We should have maxed out on event fetcher threads
-            self.assertEqual(self.store._event_fetch_ongoing, EVENT_QUEUE_THREADS)
-
-            # All the event fetchers will fail
-            self.pump()
-            self.assertEqual(self.store._event_fetch_ongoing, 0)
-
-            for event_deferred in event_deferreds:
-                failure = self.get_failure(event_deferred, Exception)
-                self.assertEqual(
-                    str(failure.value), "Could not connect to the database."
-                )
+        with self.assertLogs(
+            "synapse.metrics.background_process_metrics", level="ERROR"
+        ):
+            with self._outage():
+                # Kick off a bunch of event fetches but do not pump the reactor
+                event_deferreds = []
+                for event_id in self.event_ids:
+                    d = ensureDeferred(self.store.get_event(event_id))
+                    # Prevent the failures from being logged as unhandled by adding
+                    # a no-op errback.
+                    d.addErrback(lambda failure: failure)
+                    event_deferreds.append(d)
+
+                # We should have maxed out on event fetcher threads
+                self.assertEqual(self.store._event_fetch_ongoing, EVENT_QUEUE_THREADS)
+
+                # All the event fetchers will fail
+                self.pump()
+                self.assertEqual(self.store._event_fetch_ongoing, 0)
+
+                for event_deferred in event_deferreds:
+                    failure = self.get_failure(event_deferred, Exception)
+                    self.assertEqual(
+                        str(failure.value), "Could not connect to the database."
+                    )
 
         # This next event fetch should succeed
         self.get_success(self.store.get_event(self.event_ids[0]))