Introduce flag to use pickle for serialization (#5805)

python/ray/node.py

@@ -264,6 +264,10 @@ class Node(object):
     def load_code_from_local(self):
         return self._ray_params.load_code_from_local
 
+    @property
+    def use_pickle(self):
+        return self._ray_params.use_pickle
+
     @property
     def object_id_seed(self):
         """Get the seed for deterministic generation of object IDs"""
@@ -520,7 +524,7 @@ class Node(object):
             include_java=self._ray_params.include_java,
             java_worker_options=self._ray_params.java_worker_options,
             load_code_from_local=self._ray_params.load_code_from_local,
-        )
+            use_pickle=self._ray_params.use_pickle)
         assert ray_constants.PROCESS_TYPE_RAYLET not in self.all_processes
         self.all_processes[ray_constants.PROCESS_TYPE_RAYLET] = [process_info]