From 01b19bafb224ddd2b7cc3aef557274ffb38c9c42 Mon Sep 17 00:00:00 2001
From: Simon Mo <simon.mo@hey.com>
Date: Fri, 23 Dec 2022 15:19:38 -0800
Subject: [PATCH] [Serve] Address incremental memory leak due to _PyObjScanner
 (#31317)

---
 python/ray/dag/dag_node.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/python/ray/dag/dag_node.py b/python/ray/dag/dag_node.py
index f7a328506328..f2f615e85224 100644
--- a/python/ray/dag/dag_node.py
+++ b/python/ray/dag/dag_node.py
@@ -175,6 +175,7 @@ def _get_all_child_nodes(self) -> List["DAGNode"]:
         ):
             if n not in children:
                 children.append(n)
+        scanner.clear()
         return children
 
     def _apply_and_replace_all_child_nodes(
@@ -210,6 +211,7 @@ def _apply_and_replace_all_child_nodes(
         new_args, new_kwargs, new_other_args_to_resolve = scanner.replace_nodes(
             replace_table
         )
+        scanner.clear()
 
         # Return updated copy of self.
         return self._copy(
@@ -288,6 +290,7 @@ def apply_functional(
                 replace_table[node] = apply_fn(node)
 
         replaced_inputs = scanner.replace_nodes(replace_table)
+        scanner.clear()
 
         return replaced_inputs