Wakeup when there is a new node connection pending

Author: dpkp

kafka/client_async.py

@@ -356,6 +356,10 @@ def maybe_connect(self, node_id):
         """Queues a node for asynchronous connection during the next .poll()"""
         if self._can_connect(node_id):
             self._connecting.add(node_id)
+            # Wakeup signal is useful in case another thread is
+            # blocked waiting for incoming network traffic while holding
+            # the client lock in poll().
+            self.wakeup()
             return True
         return False