perf(config): enforcing atom key path in hotcode path

apps/emqx/src/emqx.erl

@@ -184,11 +184,18 @@ run_fold_hook(HookPoint, Args, Acc) ->
 
 -spec get_config(emqx_utils_maps:config_key_path()) -> term().
 get_config(KeyPath) ->
-    emqx_config:get(KeyPath).
+    KeyPath1 = emqx_config:ensure_atom_conf_path(KeyPath, {raise_error, config_not_found}),
+    emqx_config:get(KeyPath1).
 
 -spec get_config(emqx_utils_maps:config_key_path(), term()) -> term().
 get_config(KeyPath, Default) ->
-    emqx_config:get(KeyPath, Default).
+    try
+        KeyPath1 = emqx_config:ensure_atom_conf_path(KeyPath, {raise_error, config_not_found}),
+        emqx_config:get(KeyPath1, Default)
+    catch
+        error:config_not_found ->
+            Default
+    end.
 
 -spec get_raw_config(emqx_utils_maps:config_key_path()) -> term().
 get_raw_config(KeyPath) ->

apps/emqx/src/emqx_config.erl

@@ -88,6 +88,8 @@
     remove_handlers/0
 ]).
 
+-export([ensure_atom_conf_path/2]).
+
 -ifdef(TEST).
 -export([erase_all/0]).
 -endif.
@@ -113,7 +115,8 @@
     update_cmd/0,
     update_args/0,
     update_error/0,
-    update_result/0
+    update_result/0,
+    runtime_config_key_path/0
 ]).
 
 -type update_request() :: term().
@@ -144,6 +147,8 @@
 -type config() :: #{atom() => term()} | list() | undefined.
 -type app_envs() :: [proplists:property()].
 
+-type runtime_config_key_path() :: [atom()].
+
 %% @doc For the given path, get root value enclosed in a single-key map.
 -spec get_root(emqx_utils_maps:config_key_path()) -> map().
 get_root([RootName | _]) ->
@@ -156,25 +161,21 @@ get_root_raw([RootName | _]) ->
 
 %% @doc Get a config value for the given path.
 %% The path should at least include root config name.
--spec get(emqx_utils_maps:config_key_path()) -> term().
+-spec get(runtime_config_key_path()) -> term().
 get(KeyPath) -> do_get(?CONF, KeyPath).
 
--spec get(emqx_utils_maps:config_key_path(), term()) -> term().
+-spec get(runtime_config_key_path(), term()) -> term().
 get(KeyPath, Default) -> do_get(?CONF, KeyPath, Default).
 
--spec find(emqx_utils_maps:config_key_path()) ->
+-spec find(runtime_config_key_path()) ->
     {ok, term()} | {not_found, emqx_utils_maps:config_key_path(), term()}.
 find([]) ->
     case do_get(?CONF, [], ?CONFIG_NOT_FOUND_MAGIC) of
         ?CONFIG_NOT_FOUND_MAGIC -> {not_found, []};
         Res -> {ok, Res}
     end;
-find(KeyPath) ->
-    atom_conf_path(
-        KeyPath,
-        fun(AtomKeyPath) -> emqx_utils_maps:deep_find(AtomKeyPath, get_root(KeyPath)) end,
-        {return, {not_found, KeyPath}}
-    ).
+find(AtomKeyPath) ->
+    emqx_utils_maps:deep_find(AtomKeyPath, get_root(AtomKeyPath)).
 
 -spec find_raw(emqx_utils_maps:config_key_path()) ->
     {ok, term()} | {not_found, emqx_utils_maps:config_key_path(), term()}.
@@ -712,21 +713,14 @@ do_put(Type, Putter, [RootName | KeyPath], DeepValue) ->
     NewValue = do_deep_put(Type, Putter, KeyPath, OldValue, DeepValue),
     persistent_term:put(?PERSIS_KEY(Type, RootName), NewValue).
 
-do_deep_get(?CONF, KeyPath, Map, Default) ->
-    atom_conf_path(
-        KeyPath,
-        fun(AtomKeyPath) -> emqx_utils_maps:deep_get(AtomKeyPath, Map, Default) end,
-        {return, Default}
-    );
+do_deep_get(?CONF, AtomKeyPath, Map, Default) ->
+    emqx_utils_maps:deep_get(AtomKeyPath, Map, Default);
 do_deep_get(?RAW_CONF, KeyPath, Map, Default) ->
     emqx_utils_maps:deep_get([bin(Key) || Key <- KeyPath], Map, Default).
 
 do_deep_put(?CONF, Putter, KeyPath, Map, Value) ->
-    atom_conf_path(
-        KeyPath,
-        fun(AtomKeyPath) -> Putter(AtomKeyPath, Map, Value) end,
-        {raise_error, {not_found, KeyPath}}
-    );
+    AtomKeyPath = ensure_atom_conf_path(KeyPath, {raise_error, {not_found, KeyPath}}),
+    Putter(AtomKeyPath, Map, Value);
 do_deep_put(?RAW_CONF, Putter, KeyPath, Map, Value) ->
     Putter([bin(Key) || Key <- KeyPath], Map, Value).
 
@@ -773,15 +767,24 @@ conf_key(?CONF, RootName) ->
 conf_key(?RAW_CONF, RootName) ->
     bin(RootName).
 
-atom_conf_path(Path, ExpFun, OnFail) ->
-    try [atom(Key) || Key <- Path] of
-        AtomKeyPath -> ExpFun(AtomKeyPath)
+ensure_atom_conf_path(Path, OnFail) ->
+    case lists:all(fun erlang:is_atom/1, Path) of
+        true ->
+            %% Do not try to build new atom PATH if it already is.
+            Path;
+        _ ->
+            to_atom_conf_path(Path, OnFail)
+    end.
+
+to_atom_conf_path(Path, OnFail) ->
+    try
+        [atom(Key) || Key <- Path]
     catch
         error:badarg ->
             case OnFail of
-                {return, Val} ->
-                    Val;
                 {raise_error, Err} ->
-                    error(Err)
+                    error(Err);
+                {return, V} ->
+                    V
             end
     end.

apps/emqx/src/emqx_shared_sub.erl

@@ -158,9 +158,18 @@ dispatch(Group, Topic, Delivery = #delivery{message = Msg}, FailedSubs) ->
 
 -spec strategy(emqx_topic:group()) -> strategy().
 strategy(Group) ->
-    case emqx:get_config([broker, shared_subscription_group, Group, strategy], undefined) of
-        undefined -> emqx:get_config([broker, shared_subscription_strategy]);
-        Strategy -> Strategy
+    try
+        emqx:get_config([
+            broker,
+            shared_subscription_group,
+            binary_to_existing_atom(Group),
+            strategy
+        ])
+    catch
+        error:{config_not_found, _} ->
+            get_default_shared_subscription_strategy();
+        error:badarg ->
+            get_default_shared_subscription_strategy()
     end.
 
 -spec ack_enabled() -> boolean().
@@ -544,3 +553,6 @@ delete_route_if_needed({Group, Topic} = GroupTopic) ->
     if_no_more_subscribers(GroupTopic, fun() ->
         ok = emqx_router:do_delete_route(Topic, {Group, node()})
     end).
+
+get_default_shared_subscription_strategy() ->
+    emqx:get_config([broker, shared_subscription_strategy]).

apps/emqx/test/emqx_SUITE.erl

@@ -156,6 +156,19 @@ t_cluster_nodes(_) ->
     ?assertEqual(Expected, emqx:cluster_nodes(cores)),
     ?assertEqual([], emqx:cluster_nodes(stopped)).
 
+t_get_config(_) ->
+    ?assertEqual(false, emqx:get_config([overload_protection, enable])),
+    ?assertEqual(false, emqx:get_config(["overload_protection", <<"enable">>])).
+
+t_get_config_default_1(_) ->
+    ?assertEqual(false, emqx:get_config([overload_protection, enable], undefined)),
+    ?assertEqual(false, emqx:get_config(["overload_protection", <<"enable">>], undefined)).
+
+t_get_config_default_2(_) ->
+    AtomPathRes = emqx:get_config([overload_protection, <<"_!no_@exist_">>], undefined),
+    NonAtomPathRes = emqx:get_config(["doesnotexist", <<"db_backend">>], undefined),
+    ?assertEqual(undefined, NonAtomPathRes),
+    ?assertEqual(undefined, AtomPathRes).
 %%--------------------------------------------------------------------
 %% Hook fun
 %%--------------------------------------------------------------------

apps/emqx_authn/src/emqx_authn_api.erl

@@ -805,7 +805,11 @@ with_listener(ListenerID, Fun) ->
 find_listener(ListenerID) ->
     case binary:split(ListenerID, <<":">>) of
         [BType, BName] ->
-            case emqx_config:find([listeners, BType, BName]) of
+            case
+                emqx_config:find([
+                    listeners, binary_to_existing_atom(BType), binary_to_existing_atom(BName)
+                ])
+            of
                 {ok, _} ->
                     {ok, {BType, BName}};
                 {not_found, _, _} ->

apps/emqx_bridge/src/emqx_bridge_api.erl

@@ -687,11 +687,15 @@ get_metrics_from_local_node(BridgeType, BridgeName) ->
     ).
 
 is_enabled_bridge(BridgeType, BridgeName) ->
-    try emqx:get_config([bridges, BridgeType, BridgeName]) of
+    try emqx:get_config([bridges, BridgeType, binary_to_existing_atom(BridgeName)]) of
         ConfMap ->
             maps:get(enable, ConfMap, false)
     catch
         error:{config_not_found, _} ->
+            throw(not_found);
+        error:badarg ->
+            %% catch non-existing atom,
+            %% none-existing atom means it is not available in config PT storage.
             throw(not_found)
     end.
 

apps/emqx_conf/src/emqx_cluster_rpc_cleaner.erl

@@ -38,8 +38,8 @@
 ]).
 
 start_link() ->
-    MaxHistory = emqx_conf:get(["node", "cluster_call", "max_history"], 100),
-    CleanupMs = emqx_conf:get(["node", "cluster_call", "cleanup_interval"], 5 * 60 * 1000),
+    MaxHistory = emqx_conf:get([node, cluster_call, max_history], 100),
+    CleanupMs = emqx_conf:get([node, cluster_call, cleanup_interval], 5 * 60 * 1000),
     start_link(MaxHistory, CleanupMs).
 
 start_link(MaxHistory, CleanupMs) ->

changes/ce/perf-10698.en.md

@@ -0,0 +1 @@
+Optimize memory usage when accessing the configuration during runtime.

changes/ce/perf-10698.zh.md

@@ -0,0 +1,5 @@
+在运行时降低读取配置的内存占用。
+
+
+
+

lib-ee/emqx_ee_schema_registry/src/emqx_ee_schema_registry.app.src

@@ -1,6 +1,6 @@
 {application, emqx_ee_schema_registry, [
     {description, "EMQX Schema Registry"},
-    {vsn, "0.1.2"},
+    {vsn, "0.1.3"},
     {registered, [emqx_ee_schema_registry_sup]},
     {mod, {emqx_ee_schema_registry_app, []}},
     {applications, [

lib-ee/emqx_ee_schema_registry/src/emqx_ee_schema_registry.erl

@@ -58,7 +58,11 @@ get_serde(SchemaName) ->
 
 -spec get_schema(schema_name()) -> {ok, map()} | {error, not_found}.
 get_schema(SchemaName) ->
-    case emqx_config:get([?CONF_KEY_ROOT, schemas, SchemaName], undefined) of
+    case
+        emqx_config:get(
+            [?CONF_KEY_ROOT, schemas, binary_to_atom(SchemaName)], undefined
+        )
+    of
         undefined ->
             {error, not_found};
         Config ->