From 72f9fc5f1187abd74193568ceb55422afe3e2b99 Mon Sep 17 00:00:00 2001
From: Liangsheng Yin <hnyls2002@gmail.com>
Date: Mon, 8 Sep 2025 17:43:23 +0800
Subject: [PATCH] Monkey patch uvicorn multi worker `is_alive` timeout (#10159)

Co-authored-by: Huang Long <121648372+llll114@users.noreply.github.com>
---
 python/sglang/srt/entrypoints/http_server.py      |  4 ++++
 .../sglang/srt/managers/multi_tokenizer_mixin.py  | 15 +++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/python/sglang/srt/entrypoints/http_server.py b/python/sglang/srt/entrypoints/http_server.py
index 110292114..9adac76ce 100644
--- a/python/sglang/srt/entrypoints/http_server.py
+++ b/python/sglang/srt/entrypoints/http_server.py
@@ -93,6 +93,7 @@ from sglang.srt.managers.io_struct import (
 from sglang.srt.managers.multi_tokenizer_mixin import (
     MultiTokenizerManager,
     get_main_process_id,
+    monkey_patch_uvicorn_multiprocessing,
     read_from_shared_memory,
     write_data_for_multi_tokenizer,
 )
@@ -1219,6 +1220,9 @@ def launch_server(
                 "level": "INFO",
                 "propagate": False,
             }
+
+            monkey_patch_uvicorn_multiprocessing()
+
             uvicorn.run(
                 "sglang.srt.entrypoints.http_server:app",
                 host=server_args.host,
diff --git a/python/sglang/srt/managers/multi_tokenizer_mixin.py b/python/sglang/srt/managers/multi_tokenizer_mixin.py
index e4f83c82b..8274003ad 100644
--- a/python/sglang/srt/managers/multi_tokenizer_mixin.py
+++ b/python/sglang/srt/managers/multi_tokenizer_mixin.py
@@ -19,6 +19,7 @@ import os
 import pickle
 import sys
 import threading
+from functools import partialmethod
 from multiprocessing import shared_memory
 from typing import Any, Dict
 
@@ -556,3 +557,17 @@ def write_data_for_multi_tokenizer(
     args_shm.close()
 
     return args_shm
+
+
+def monkey_patch_uvicorn_multiprocessing(timeout: float = 10):
+    """Monkey patch uvicorn multiprocessing is_alive timeout"""
+    # from default 5s -> 10s
+    try:
+        from uvicorn.supervisors.multiprocess import Process
+
+        Process.is_alive = partialmethod(Process.is_alive, timeout=timeout)
+
+    except ImportError:
+        logger.warning(
+            "uvicorn.supervisors.multiprocess not found, skipping monkey patch"
+        )