diff --git a/apps/emqx/src/config/emqx_config_logger.erl b/apps/emqx/src/config/emqx_config_logger.erl
index bc284732b..fca6ebc43 100644
--- a/apps/emqx/src/config/emqx_config_logger.erl
+++ b/apps/emqx/src/config/emqx_config_logger.erl
@@ -31,14 +31,12 @@ remove_handler() ->
     ok = emqx_config_handler:remove_handler(?LOG),
     ok.
 
-post_config_update(?LOG, _Req, NewConf, _OldConf, _AppEnvs) ->
-    NewLog = #{log => NewConf},
-    [{"logger_level", LevelFunc}, {"logger", LoggerFunc}] =
-        emqx_conf_schema:translation("kernel"),
-    NewHandlers = LoggerFunc(NewLog),
-    Level = LevelFunc(NewLog),
+post_config_update(?LOG, _Req, _NewConf, _OldConf, AppEnvs) ->
+    Kernel = proplists:get_value(kernel, AppEnvs),
+    NewHandlers = proplists:get_value(logger, Kernel, []),
+    Level = proplists:get_value(logger_level, Kernel, warning),
     ok = update_log_handlers(NewHandlers),
-    ok = logger:set_primary_config(level, Level),
+    ok = emqx_logger:set_primary_log_level(Level),
     application:set_env(kernel, logger_level, Level),
     ok;
 post_config_update(_ConfPath, _Req, _NewConf, _OldConf, _AppEnvs) ->
diff --git a/apps/emqx/src/emqx_config_handler.erl b/apps/emqx/src/emqx_config_handler.erl
index 750f89dd2..0282e5f8e 100644
--- a/apps/emqx/src/emqx_config_handler.erl
+++ b/apps/emqx/src/emqx_config_handler.erl
@@ -396,14 +396,29 @@ assert_callback_function(Mod) ->
     end,
     ok.
 
+-spec schema(module(), emqx_map_lib:config_key_path()) -> hocon_schema:schema().
 schema(SchemaModule, [RootKey | _]) ->
     Roots = hocon_schema:roots(SchemaModule),
-    Field =
+    {Field, Translations} =
         case lists:keyfind(bin(RootKey), 1, Roots) of
             {_, {Ref, ?REF(Ref)}} -> {Ref, ?R_REF(SchemaModule, Ref)};
-            {_, Field0} -> Field0
+            {_, {Name, Field0}} ->
+                case maps:take(translate_to, Field0) of
+                    {TRs, Field1} ->
+                        {
+                            {Name, Field1},
+                            lists:foldl(fun(T, Acc) ->
+                                Acc#{T => hocon_schema:translation(SchemaModule, T)}
+                                      end, #{}, TRs)
+                        };
+                    error -> {{Name, Field0}, #{}}
+                end
         end,
-    #{roots => [Field]}.
+    #{
+        roots => [Field],
+        translations => Translations,
+        validations => hocon_schema:validations(SchemaModule)
+    }.
 
 load_prev_handlers() ->
     Handlers = application:get_env(emqx, ?MODULE, #{}),
diff --git a/apps/emqx/src/emqx_flapping.erl b/apps/emqx/src/emqx_flapping.erl
index f4b05b7ff..c69208c22 100644
--- a/apps/emqx/src/emqx_flapping.erl
+++ b/apps/emqx/src/emqx_flapping.erl
@@ -149,7 +149,7 @@ handle_info({timeout, _TRef, {garbage_collect, Zone}}, State) ->
                 - maps:get(window_time, get_policy(Zone)),
     MatchSpec = [{{'_', '_', '_', '$1', '_'},[{'<', '$1', Timestamp}], [true]}],
     ets:select_delete(?FLAPPING_TAB, MatchSpec),
-    start_timer(Zone),
+    _ = start_timer(Zone),
     {noreply, State, hibernate};
 
 handle_info(Info, State) ->
diff --git a/apps/emqx/src/emqx_vm_mon.erl b/apps/emqx/src/emqx_vm_mon.erl
index 18005dce5..e763c7bfb 100644
--- a/apps/emqx/src/emqx_vm_mon.erl
+++ b/apps/emqx/src/emqx_vm_mon.erl
@@ -45,7 +45,7 @@ start_link() ->
 %%--------------------------------------------------------------------
 
 init([]) ->
-    start_check_timer(),
+    _ = start_check_timer(),
     {ok, #{}}.
 
 handle_call(Req, _From, State) ->
@@ -82,7 +82,7 @@ handle_info({timeout, _Timer, check}, State) ->
         _Precent ->
             ok
     end,
-    start_check_timer(),
+    _ = start_check_timer(),
     {noreply, State};
 
 handle_info(Info, State) ->
diff --git a/apps/emqx_conf/src/emqx_conf_schema.erl b/apps/emqx_conf/src/emqx_conf_schema.erl
index e9cca65a5..b0d467e34 100644
--- a/apps/emqx_conf/src/emqx_conf_schema.erl
+++ b/apps/emqx_conf/src/emqx_conf_schema.erl
@@ -75,17 +75,20 @@ roots() ->
        sc(ref("node"),
           #{ desc => "Node name, cookie, config & data directories "
                      "and the Erlang virtual machine (BEAM) boot parameters."
+           , translate_to => ["emqx"]
            })}
     , {"cluster",
        sc(ref("cluster"),
           #{ desc => "EMQX nodes can form a cluster to scale up the total capacity.<br>"
                      "Here holds the configs to instruct how individual nodes "
                      "can discover each other."
+            , translate_to => ["ekka"]
            })}
     , {"log",
        sc(ref("log"),
           #{ desc => "Configure logging backends (to console or to file), "
                      "and logging level for each logger backend."
+           , translate_to => ["kernel"]
            })}
     , {"rpc",
        sc(ref("rpc"),
@@ -93,6 +96,7 @@ roots() ->
                      "inter-broker communication.<br/>Most of the time the default config "
                      "should work, but in case you need to do performance "
                      "fine-turning or experiment a bit, this is where to look."
+           , translate_to => ["gen_rpc"]
            })}
     , {"db",
        sc(ref("db"),
@@ -737,6 +741,7 @@ tr_cluster_discovery(Conf) ->
     Strategy = conf_get("cluster.discovery_strategy", Conf),
     {Strategy, filter(options(Strategy, Conf))}.
 
+-spec tr_logger_level(hocon:config()) -> logger:level().
 tr_logger_level(Conf) ->
     ConsoleLevel = conf_get("log.console_handler.level", Conf, undefined),
     FileLevels = [conf_get("level", SubConf) || {_, SubConf}
diff --git a/apps/emqx_management/test/emqx_mgmt_api_configs_SUITE.erl b/apps/emqx_management/test/emqx_mgmt_api_configs_SUITE.erl
index dc944c9e7..77fae29be 100644
--- a/apps/emqx_management/test/emqx_mgmt_api_configs_SUITE.erl
+++ b/apps/emqx_management/test/emqx_mgmt_api_configs_SUITE.erl
@@ -71,11 +71,30 @@ t_update(_Config) ->
 t_log(_Config) ->
     {ok, Log} = get_config("log"),
     File = "log/emqx-test.log",
+    %% update handler
     Log1 = emqx_map_lib:deep_put([<<"file_handlers">>, <<"default">>, <<"enable">>], Log, true),
     Log2 = emqx_map_lib:deep_put([<<"file_handlers">>, <<"default">>, <<"file">>], Log1, File),
     {ok, #{}} = update_config(<<"log">>, Log2),
     {ok, Log3} = logger:get_handler_config(default),
     ?assertMatch(#{config := #{file := File}}, Log3),
+    ErrLog1 = emqx_map_lib:deep_put([<<"file_handlers">>, <<"default">>, <<"enable">>], Log, 1),
+    ?assertMatch({error, {"HTTP/1.1", 400, _}}, update_config(<<"log">>, ErrLog1)),
+    ErrLog2 = emqx_map_lib:deep_put([<<"file_handlers">>, <<"default">>, <<"enabfe">>], Log, true),
+    ?assertMatch({error, {"HTTP/1.1", 400, _}}, update_config(<<"log">>, ErrLog2)),
+
+    %% add new handler
+    File1 = "log/emqx-test1.log",
+    Handler = emqx_map_lib:deep_get([<<"file_handlers">>, <<"default">>], Log2),
+    NewLog1 = emqx_map_lib:deep_put([<<"file_handlers">>, <<"new">>], Log2, Handler),
+    NewLog2 = emqx_map_lib:deep_put([<<"file_handlers">>, <<"new">>, <<"file">>], NewLog1, File1),
+    {ok, #{}} = update_config(<<"log">>, NewLog2),
+    {ok, Log4} = logger:get_handler_config(new),
+    ?assertMatch(#{config := #{file := File1}}, Log4),
+
+    %% disable new handler
+    Disable = emqx_map_lib:deep_put([<<"file_handlers">>, <<"new">>, <<"enable">>], NewLog2, false),
+    {ok, #{}} = update_config(<<"log">>, Disable),
+    ?assertEqual({error, {not_found, new}}, logger:get_handler_config(new)),
     ok.
 
 t_zones(_Config) ->
diff --git a/apps/emqx_plugin_libs/src/emqx_plugin_libs_ssl.erl b/apps/emqx_plugin_libs/src/emqx_plugin_libs_ssl.erl
index 8da9198db..770c05045 100644
--- a/apps/emqx_plugin_libs/src/emqx_plugin_libs_ssl.erl
+++ b/apps/emqx_plugin_libs/src/emqx_plugin_libs_ssl.erl
@@ -78,7 +78,8 @@ save_files_return_opts(Options, Dir) ->
     Versions = emqx_tls_lib:integral_versions(Get(versions)),
     Ciphers = emqx_tls_lib:integral_ciphers(Versions, Get(ciphers)),
     filter([{keyfile, Key}, {certfile, Cert}, {cacertfile, CA},
-            {verify, Verify}, {server_name_indication, SNI}, {versions, Versions}, {ciphers, Ciphers}]).
+            {verify, Verify}, {server_name_indication, SNI},
+            {versions, Versions}, {ciphers, Ciphers}]).
 
 %% @doc Save a key or certificate file in data dir,
 %% and return path of the saved file.