[Serve] Wait for actor name to be cleaned up (#12215)

python/ray/serve/api.py

@@ -1,4 +1,5 @@
 import atexit
+import time
 from functools import wraps
 import os
 from uuid import UUID
@@ -81,9 +82,25 @@ class Client:
         Shuts down all processes and deletes all state associated with the
         instance.
         """
-        if not self._shutdown:
+        if (not self._shutdown) and ray.is_initialized():
             ray.get(self._controller.shutdown.remote())
             ray.kill(self._controller, no_restart=True)
+
+            # Wait for the named actor entry gets removed as well.
+            started = time.time()
+            while True:
+                try:
+                    ray.get_actor(self._controller_name)
+                    if time.time() - started > 5:
+                        logger.warning(
+                            "Waited 5s for Serve to shutdown gracefully but "
+                            "the controller is still not cleaned up. "
+                            "You can ignore this warning if you are shutting "
+                            "down the Ray cluster.")
+                        break
+                except ValueError:  # actor name is removed
+                    break
+
             self._shutdown = True
 
     @_ensure_connected