fix(limiter): add config update handler for limiter

apps/emqx/src/emqx_limiter/src/emqx_limiter_manager.erl

@@ -29,7 +29,8 @@
     find_bucket/2,
     insert_bucket/2, insert_bucket/3,
     make_path/2,
-    restart_server/1
+    restart_server/1,
+    post_config_update/5
 ]).
 
 %% gen_server callbacks
@@ -68,7 +69,7 @@ start_server(Type) ->
 
 -spec restart_server(limiter_type()) -> _.
 restart_server(Type) ->
-    emqx_limiter_server_sup:restart(Type).
+    emqx_limiter_server:restart(Type).
 
 -spec find_bucket(limiter_type(), bucket_name()) ->
     {ok, bucket_ref()} | undefined.
@@ -100,6 +101,10 @@ insert_bucket(Path, Bucket) ->
 make_path(Type, BucketName) ->
     [Type | BucketName].
 
+post_config_update([limiter, Type], _Config, NewConf, _OldConf, _AppEnvs) ->
+    Config = maps:get(Type, NewConf),
+    emqx_limiter_server:update_config(Type, Config).
+
 %%--------------------------------------------------------------------
 %% @doc
 %% Starts the server
@@ -130,6 +135,7 @@ start_link() ->
     | {stop, Reason :: term()}
     | ignore.
 init([]) ->
+    emqx_conf:add_handler([limiter], ?MODULE),
     _ = ets:new(?TAB, [
         set,
         public,
@@ -204,6 +210,7 @@ handle_info(Info, State) ->
     State :: term()
 ) -> any().
 terminate(_Reason, _State) ->
+    emqx_conf:remove_handler([limiter]),
     ok.
 
 %%--------------------------------------------------------------------

apps/emqx/src/emqx_limiter/src/emqx_limiter_server.erl

@@ -46,7 +46,8 @@
     info/1,
     name/1,
     get_initial_val/1,
-    update_config/1
+    restart/1,
+    update_config/2
 ]).
 
 %% number of tokens generated per period
@@ -87,7 +88,9 @@
 -type decimal() :: emqx_limiter_decimal:decimal().
 -type index() :: pos_integer().
 
--define(CALL(Type), gen_server:call(name(Type), ?FUNCTION_NAME)).
+-define(CALL(Type, Msg), gen_server:call(name(Type), Msg)).
+-define(CALL(Type), ?CALL(Type, ?FUNCTION_NAME)).
+
 %% minimum coefficient for overloaded limiter
 -define(OVERLOAD_MIN_ALLOC, 0.3).
 -define(CURRYING(X, F2), fun(Y) -> F2(X, Y) end).
@@ -145,10 +148,14 @@ info(Type) ->
 name(Type) ->
     erlang:list_to_atom(io_lib:format("~s_~s", [?MODULE, Type])).
 
--spec update_config(limiter_type()) -> ok.
+-spec restart(limiter_type()) -> ok.
-update_config(Type) ->
+restart(Type) ->
     ?CALL(Type).
 
+-spec update_config(limiter_type(), hocons:config()) -> ok.
+update_config(Type, Config) ->
+    ?CALL(Type, {update_config, Type, Config}).
+
 %%--------------------------------------------------------------------
 %% @doc
 %% Starts the server
@@ -197,9 +204,12 @@ init([Type]) ->
     | {stop, Reason :: term(), NewState :: term()}.
 handle_call(info, _From, State) ->
     {reply, State, State};
-handle_call(update_config, _From, #{type := Type}) ->
+handle_call(restart, _From, #{type := Type}) ->
     NewState = init_tree(Type),
     {reply, ok, NewState};
+handle_call({update_config, Type, Config}, _From, #{type := Type}) ->
+    NewState = init_tree(Type, Config),
+    {reply, ok, NewState};
 handle_call(Req, _From, State) ->
     ?SLOG(error, #{msg => "unexpected_call", call => Req}),
     {reply, ignored, State}.
@@ -442,7 +452,11 @@ dispatch_burst_to_buckets([], _, Alloced, Buckets) ->
     {Alloced, Buckets}.
 
 -spec init_tree(emqx_limiter_schema:limiter_type()) -> state().
-init_tree(Type) ->
+init_tree(Type) when is_atom(Type) ->
+    Cfg = emqx:get_config([limiter, Type]),
+    init_tree(Type, Cfg).
+
+init_tree(Type, #{bucket := Buckets} = Cfg) ->
     State = #{
         type => Type,
         root => undefined,
@@ -451,7 +465,6 @@ init_tree(Type) ->
         buckets => #{}
     },
 
-    #{bucket := Buckets} = Cfg = emqx:get_config([limiter, Type]),
     {Factor, Root} = make_root(Cfg),
     {CounterNum, DelayBuckets} = make_bucket(maps:to_list(Buckets), Type, Cfg, Factor, 1, []),
 

apps/emqx/src/emqx_limiter/src/emqx_limiter_server_sup.erl

@@ -19,7 +19,7 @@
 -behaviour(supervisor).
 
 %% API
--export([start_link/0, start/1, restart/1]).
+-export([start_link/0, start/1]).
 
 %% Supervisor callbacks
 -export([init/1]).
@@ -47,13 +47,6 @@ start(Type) ->
     Spec = make_child(Type),
     supervisor:start_child(?MODULE, Spec).
 
-%% XXX This is maybe a workaround, not so good
--spec restart(emqx_limiter_schema:limiter_type()) -> _.
-restart(Type) ->
-    Id = emqx_limiter_server:name(Type),
-    _ = supervisor:terminate_child(?MODULE, Id),
-    supervisor:restart_child(?MODULE, Id).
-
 %%--------------------------------------------------------------------
 %%  Supervisor callbacks
 %%--------------------------------------------------------------------

apps/emqx/test/emqx_ratelimiter_SUITE.erl

@@ -733,7 +733,7 @@ with_config(Path, Modifier, Case) ->
     NewCfg = Modifier(Cfg),
     ct:pal("test with config:~p~n", [NewCfg]),
     emqx_config:put(Path, NewCfg),
-    emqx_limiter_server:update_config(message_routing),
+    emqx_limiter_server:restart(message_routing),
     timer:sleep(500),
     DelayReturn = delay_return(Case),
     emqx_config:put(Path, Cfg),

apps/emqx/test/emqx_ws_connection_SUITE.erl

@@ -483,7 +483,7 @@ t_ensure_rate_limit(_) ->
     PerClient = emqx_config:get(Path),
     {ok, Rate} = emqx_limiter_schema:to_rate("50MB"),
     emqx_config:put(Path, PerClient#{rate := Rate}),
-    emqx_limiter_server:update_config(bytes_in),
+    emqx_limiter_server:restart(bytes_in),
     timer:sleep(100),
 
     Limiter = init_limiter(),
@@ -502,7 +502,7 @@ t_ensure_rate_limit(_) ->
     ?assertEqual([{active, false}], ?ws_conn:info(postponed, St1)),
 
     emqx_config:put(Path, PerClient),
-    emqx_limiter_server:update_config(bytes_in),
+    emqx_limiter_server:restart(bytes_in),
     timer:sleep(100).
 
 t_parse_incoming(_) ->