Silence control conn errors around shutdown

cassandra/cluster.py

@@ -1440,7 +1440,7 @@ class ControlConnection(object):
         if self._is_shutdown:
             return
 
-        self._cluster.executor.submit(self._reconnect)
+        self._submit(self._reconnect)
 
     def _reconnect(self):
         log.debug("[control connection] Attempting to reconnect")
@@ -1479,6 +1479,14 @@ class ControlConnection(object):
             self._reconnection_handler = new_handler
             return old
 
+    def _submit(self, *args, **kwargs):
+        try:
+            if not self._cluster._is_shutdown:
+                return self._cluster.executor.submit(*args, **kwargs)
+        except ReferenceError:
+            pass
+        return None
+
     def shutdown(self):
         with self._lock:
             if self._is_shutdown:
@@ -1504,6 +1512,9 @@ class ControlConnection(object):
             self._signal_error()
 
     def _refresh_schema(self, connection, keyspace=None, table=None):
+        if self._cluster._is_shutdown:
+            return
+
         self.wait_for_schema_agreement(connection)
 
         where_clause = ""
@@ -1645,9 +1656,9 @@ class ControlConnection(object):
         table = event['table'] or None
         if event['change_type'] in ("CREATED", "DROPPED"):
             keyspace = keyspace if table else None
-            self._cluster.executor.submit(self.refresh_schema, keyspace)
+            self._submit(self.refresh_schema, keyspace)
         elif event['change_type'] == "UPDATED":
-            self._cluster.executor.submit(self.refresh_schema, keyspace, table)
+            self._submit(self.refresh_schema, keyspace, table)
 
     def wait_for_schema_agreement(self, connection=None):
         # Each schema change typically generates two schema refreshes, one