diff --git a/apps/emqx/src/emqx_limiter/src/emqx_limiter_server.erl b/apps/emqx/src/emqx_limiter/src/emqx_limiter_server.erl
index 939824e02..997f6b788 100644
--- a/apps/emqx/src/emqx_limiter/src/emqx_limiter_server.erl
+++ b/apps/emqx/src/emqx_limiter/src/emqx_limiter_server.erl
@@ -75,11 +75,11 @@
 
 -type state() :: #{
     type := limiter_type(),
-    root := undefined | root(),
+    root := root(),
     buckets := buckets(),
     %% current counter to alloc
-    counter := undefined | counters:counters_ref(),
-    index := index()
+    counter := counters:counters_ref(),
+    index := 0 | index()
 }.
 
 -type buckets() :: #{bucket_name() => bucket()}.
@@ -507,7 +507,7 @@ do_add_bucket(Id, #{rate := Rate, capacity := Capacity} = Cfg, #{buckets := Buck
     end.
 
 make_bucket(Id, Cfg, #{index := ?COUNTER_SIZE} = State) ->
-    add_bucket(Id, Cfg, State#{
+    make_bucket(Id, Cfg, State#{
         counter => counters:new(?COUNTER_SIZE, [write_concurrency]),
         index => 0
     });
diff --git a/apps/emqx/src/emqx_listeners.erl b/apps/emqx/src/emqx_listeners.erl
index dcb35adbb..fdbd5350e 100644
--- a/apps/emqx/src/emqx_listeners.erl
+++ b/apps/emqx/src/emqx_listeners.erl
@@ -546,7 +546,7 @@ add_limiter_bucket(Id, #{limiter := Limiters}) ->
         ok,
         Limiters
     );
-add_limiter_bucket(_Id, _cfg) ->
+add_limiter_bucket(_Id, _Cfg) ->
     ok.
 
 del_limiter_bucket(Id, #{limiter := Limiters}) ->
@@ -556,7 +556,7 @@ del_limiter_bucket(Id, #{limiter := Limiters}) ->
         end,
         maps:keys(Limiters)
     );
-del_limiter_bucket(_Id, _cfg) ->
+del_limiter_bucket(_Id, _Cfg) ->
     ok.
 
 enable_authn(Opts) ->
diff --git a/apps/emqx_retainer/src/emqx_retainer_api.erl b/apps/emqx_retainer/src/emqx_retainer_api.erl
index 7d085b422..2c0bd725c 100644
--- a/apps/emqx_retainer/src/emqx_retainer_api.erl
+++ b/apps/emqx_retainer/src/emqx_retainer_api.erl
@@ -151,13 +151,8 @@ config(get, _) ->
     {200, emqx:get_raw_config([retainer])};
 config(put, #{body := Body}) ->
     try
-        check_bucket_exists(
-            Body,
-            fun(Conf) ->
-                {ok, _} = emqx_retainer:update_config(Conf),
-                {200, emqx:get_raw_config([retainer])}
-            end
-        )
+        {ok, _} = emqx_retainer:update_config(Body),
+        {200, emqx:get_raw_config([retainer])}
     catch
         _:Reason:_ ->
             {400, #{
@@ -237,30 +232,3 @@ check_backend(Type, Params, Cont) ->
         _ ->
             {400, 'BAD_REQUEST', <<"This API only support built in database">>}
     end.
-
-check_bucket_exists(
-    #{
-        <<"flow_control">> :=
-            #{<<"batch_deliver_limiter">> := Name} = Flow
-    } = Conf,
-    Cont
-) ->
-    case erlang:binary_to_atom(Name) of
-        '' ->
-            %% workaround, empty string means set the value to undefined,
-            %% but now, we can't store `undefined` in the config file correct,
-            %% but, we can delete this field
-            Cont(Conf#{
-                <<"flow_control">> := maps:remove(<<"batch_deliver_limiter">>, Flow)
-            });
-        Bucket ->
-            Path = emqx_limiter_schema:get_bucket_cfg_path(batch, Bucket),
-            case emqx:get_config(Path, undefined) of
-                undefined ->
-                    {400, 'BAD_REQUEST', <<"The limiter bucket not exists">>};
-                _ ->
-                    Cont(Conf)
-            end
-    end;
-check_bucket_exists(Conf, Cont) ->
-    Cont(Conf).