[Vulnerability]feat(conn): set bootstrap server host (#9931)

python/sglang/srt/disaggregation/prefill.py

@@ -23,7 +23,7 @@ import logging
 import threading
 from collections import deque
 from http import HTTPStatus
-from typing import TYPE_CHECKING, List, Optional
+from typing import TYPE_CHECKING, List, Optional, Type
 
 import torch
 
@@ -140,8 +140,10 @@ class PrefillBootstrapQueue:
         kv_args.ib_device = self.scheduler.server_args.disaggregation_ib_device
         kv_args.gpu_id = self.scheduler.gpu_id
 
-        kv_manager_class = get_kv_class(self.transfer_backend, KVClassType.MANAGER)
-        kv_manager = kv_manager_class(
+        kv_manager_class: Type[BaseKVManager] = get_kv_class(
+            self.transfer_backend, KVClassType.MANAGER
+        )
+        kv_manager: BaseKVManager = kv_manager_class(
             kv_args,
             DisaggregationMode.PREFILL,
             self.scheduler.server_args,