diff --git a/imperative/python/megengine/distributed/server.py b/imperative/python/megengine/distributed/server.py
index 27f23dfd1d1af37f09f34d215f808e88b46835bc..e83efb926c3bdaefa375eac4f264e58f57b808a8 100644
--- a/imperative/python/megengine/distributed/server.py
+++ b/imperative/python/megengine/distributed/server.py
@@ -36,6 +36,7 @@ class Methods:
         self.dict_barrier_counter = defaultdict(int)
         self.dict_barrier_event = defaultdict(threading.Event)
         self.user_dict = defaultdict(partial(Future, False))
+        self.bcast_dict = {}
 
     def connect(self):
         """Method for checking connection success."""
@@ -127,6 +128,23 @@ class Methods:
             future = self.user_dict[key]
         return future.get()
 
+    def bcast_val(self, val, key, size):
+        with self.lock:
+            if key not in self.bcast_dict:
+                self.bcast_dict[key] = [Future(False), size]
+            arr = self.bcast_dict[key]
+        if val is not None:
+            arr[0].set(val)
+            val = None
+        else:
+            val = arr[0].get()
+        with self.lock:
+            cnt = arr[1] - 1
+            arr[1] = cnt
+            if cnt == 0:
+                del self.bcast_dict[key]
+        return val
+
 
 class ThreadXMLRPCServer(ThreadingMixIn, SimpleXMLRPCServer):
     pass
@@ -142,7 +160,9 @@ def _start_server(py_server_port, queue):
     """
     try:
         mm_server_port = create_mm_server("0.0.0.0", 0)
-        server = ThreadXMLRPCServer(("0.0.0.0", py_server_port), logRequests=False)
+        server = ThreadXMLRPCServer(
+            ("0.0.0.0", py_server_port), logRequests=False, allow_none=True
+        )
         server.register_instance(Methods(mm_server_port))
         _, py_server_port = server.server_address
         queue.put((py_server_port, mm_server_port))
@@ -185,13 +205,14 @@ class Client:
         self.master_ip = master_ip
         self.port = port
         self.connect()
+        self.bcast_dict = defaultdict(lambda: 0)
 
     def connect(self):
         """Check connection success."""
         while True:
             try:
                 self.proxy = ServerProxy(
-                    "http://{}:{}".format(self.master_ip, self.port)
+                    "http://{}:{}".format(self.master_ip, self.port), allow_none=True
                 )
                 if self.proxy.connect():
                     break
@@ -247,22 +268,17 @@ class Client:
 
     def user_set(self, key, val):
         """Set user defined key-value pairs across processes."""
-        self.proxy.user_set(key, val)
+        return self.proxy.user_set(key, val)
 
     def user_get(self, key):
         """Get user defined key-value pairs across processes."""
         return self.proxy.user_get(key)
 
     def bcast_val(self, val, key, size):
-        if val is not None:
-            self.user_set(key + "_sync", val)
-            self.group_barrier(key, size)
-            self.group_barrier(key, size)
-        else:
-            self.group_barrier(key, size)
-            val = self.user_get(key + "_sync")
-            self.group_barrier(key, size)
-            return val
+        idx = self.bcast_dict[key] + 1
+        self.bcast_dict[key] = idx
+        key = key + "_bcast_" + str(idx)
+        return self.proxy.bcast_val(val, key, size)
 
 
 def main(port=0, verbose=True):