diff --git a/apps/emqx_connector/data/app.2021.06.01.22.32.03.config b/apps/emqx_connector/data/app.2021.06.01.22.32.03.config
new file mode 100644
index 000000000..29e2a1f7a
--- /dev/null
+++ b/apps/emqx_connector/data/app.2021.06.01.22.32.03.config
@@ -0,0 +1,4 @@
+[{connectors,[#{<<"id">> => <<"mysql-abc">>,
+                <<"type">> => <<"mysql_connenctor">>},
+              #{<<"id">> => <<"pgsql-123">>,
+                <<"type">> => <<"pgsql_connenctor">>}]}].
diff --git a/apps/emqx_connector/data/vm.2021.06.01.22.32.03.args b/apps/emqx_connector/data/vm.2021.06.01.22.32.03.args
new file mode 100644
index 000000000..e69de29bb
diff --git a/apps/emqx_connector/etc/emqx_connector.conf b/apps/emqx_connector/etc/emqx_connector.conf
index d93db8c34..06f25cde4 100644
--- a/apps/emqx_connector/etc/emqx_connector.conf
+++ b/apps/emqx_connector/etc/emqx_connector.conf
@@ -2,18 +2,18 @@
 ## EMQ X CONNECTOR Plugin
 ##--------------------------------------------------------------------
 
-## Base directory for emqx_connector indicating where to load configs from disk.
-##
-## Value: String
-## Default: "{{ etc_dir }}/connectors/"
-emqx_connectors: [
-    {id: "mysql-abc",
-     type: mysql_connenctor,
-     config: {}
-    },
-    {id: "pgsql-123",
-     type: pgsql_connenctor,
-     config: {}
-    },
+connectors: [
+    {id: "mysql-abc"
+     resource_type: emqx_connector_mysql
+     config: {
+        server: "127.0.0.1:3306"
+        database: mqtt
+        pool_size: 1
+        user: root
+        password: public
+        auto_reconnect: true
+        ssl: false
+     }
+    }
 ]
 
diff --git a/apps/emqx_connector/priv/emqx_connector.schema b/apps/emqx_connector/priv/emqx_connector.schema
index b8476c4d9..cdc079973 100644
--- a/apps/emqx_connector/priv/emqx_connector.schema
+++ b/apps/emqx_connector/priv/emqx_connector.schema
@@ -1,2 +1,7 @@
 %%-*- mode: erlang -*-
 %% emqx_connector config mapping
+
+{mapping, "connectors", "connectors", [
+  {default, []},
+  {datatype, string}
+]}.
\ No newline at end of file
diff --git a/apps/emqx_connector/src/emqx_connector_app.erl b/apps/emqx_connector/src/emqx_connector_app.erl
index 0e64d11bc..f554cc117 100644
--- a/apps/emqx_connector/src/emqx_connector_app.erl
+++ b/apps/emqx_connector/src/emqx_connector_app.erl
@@ -22,7 +22,7 @@ stop(_State) ->
 
 load_config() ->
     case hocon:load("etc/plugins/emqx_connector.conf", #{format => map}) of
-        {ok, #{<<"emqx_connectors">> := Connectors}} ->
+        {ok, #{<<"connectors">> := Connectors}} ->
             lists:foreach(fun load_connector/1, Connectors);
         {error, Reason} ->
             error(Reason)
diff --git a/apps/emqx_connector/src/emqx_connector_mysql.erl b/apps/emqx_connector/src/emqx_connector_mysql.erl
index ad9b9a4d1..c34d361ce 100644
--- a/apps/emqx_connector/src/emqx_connector_mysql.erl
+++ b/apps/emqx_connector/src/emqx_connector_mysql.erl
@@ -5,7 +5,9 @@
 
 -emqx_resource_api_path("connectors/mysql").
 
--export([fields/1]).
+-export([ fields/1
+        , on_config_to_file/1
+        ]).
 
 %% callbacks of behaviour emqx_resource
 -export([ on_start/2
@@ -18,10 +20,14 @@
 
 -export([do_health_check/1]).
 
+%%=====================================================================
 fields("config") ->
     emqx_connector_schema_lib:relational_db_fields() ++
     emqx_connector_schema_lib:ssl_fields().
 
+on_config_to_file(#{server := Server} = Config) ->
+    Config#{server => emqx_connector_schema_lib:ip_port_to_string(Server)}.
+
 %% ===================================================================
 
 on_start(InstId, #{server := {Host, Port},
@@ -58,7 +64,7 @@ on_query(InstId, {sql, SQL}, AfterQuery, #{poolname := PoolName} = State) ->
     case Result = ecpool:pick_and_do(PoolName, {mysql, query, [SQL]}, no_handover) of
         {error, Reason} ->
             logger:debug("mysql connector ~p do sql query failed, sql: ~p, reason: ~p", [InstId, SQL, Reason]),
-            emqx_resource:query_failure(AfterQuery);
+            emqx_resource:query_failed(AfterQuery);
         _ ->
             emqx_resource:query_success(AfterQuery)
     end,
diff --git a/apps/emqx_connector/src/emqx_connector_schema_lib.erl b/apps/emqx_connector/src/emqx_connector_schema_lib.erl
index 8e69245b9..341901750 100644
--- a/apps/emqx_connector/src/emqx_connector_schema_lib.erl
+++ b/apps/emqx_connector/src/emqx_connector_schema_lib.erl
@@ -6,6 +6,7 @@
         ]).
 
 -export([ to_ip_port/1
+        , ip_port_to_string/1
         ]).
 
 -typerefl_from_string({ip_port/0, emqx_connector_schema_lib, to_ip_port}).
@@ -99,4 +100,7 @@ to_ip_port(Str) ->
                  _ -> {error, Str}
              end;
          _ -> {error, Str}
-     end.
\ No newline at end of file
+     end.
+
+ip_port_to_string({Ip, Port}) ->
+    inet:ntoa(Ip) ++ ":" ++ integer_to_list(Port).
diff --git a/apps/emqx_resource/include/emqx_resource.hrl b/apps/emqx_resource/include/emqx_resource.hrl
index 1f75b453e..123854bc9 100644
--- a/apps/emqx_resource/include/emqx_resource.hrl
+++ b/apps/emqx_resource/include/emqx_resource.hrl
@@ -15,7 +15,7 @@
 %%--------------------------------------------------------------------
 -type resource_type() :: module().
 -type instance_id() :: binary().
--type resource_config() :: jsx:json_term().
+-type resource_config() :: term().
 -type resource_spec() :: map().
 -type resource_state() :: term().
 -type resource_data() :: #{
diff --git a/apps/emqx_resource/src/emqx_resource.app.src b/apps/emqx_resource/src/emqx_resource.app.src
index af9f48cc6..13330b061 100644
--- a/apps/emqx_resource/src/emqx_resource.app.src
+++ b/apps/emqx_resource/src/emqx_resource.app.src
@@ -7,7 +7,8 @@
    [kernel,
     stdlib,
     gproc,
-    hocon
+    hocon,
+    jsx
    ]},
   {env,[]},
   {modules, []},
diff --git a/apps/emqx_resource/src/emqx_resource.erl b/apps/emqx_resource/src/emqx_resource.erl
index 00ea1f868..b5c1ce730 100644
--- a/apps/emqx_resource/src/emqx_resource.erl
+++ b/apps/emqx_resource/src/emqx_resource.erl
@@ -65,6 +65,7 @@
         , call_health_check/3 %% verify if the resource is working normally
         , call_stop/3   %% stop the instance
         , call_config_merge/4 %% merge the config when updating
+        , call_config_to_file/2
         ]).
 
 -export([ list_instances/0 %% list all the instances, id only.
@@ -85,12 +86,15 @@
                     , on_health_check/2
                     , on_api_reply_format/1
                     , on_config_merge/3
+                    , on_config_to_file/1
                     ]).
 
 -callback on_api_reply_format(resource_data()) -> map().
 
 -callback on_config_merge(resource_config(), resource_config(), term()) -> resource_config().
 
+-callback on_config_to_file(resource_config()) -> jsx:json_term().
+
 %% when calling emqx_resource:start/1
 -callback on_start(instance_id(), resource_config()) ->
     {ok, resource_state()} | {error, Reason :: term()}.
@@ -241,6 +245,10 @@ call_stop(InstId, Mod, ResourceState) ->
 call_config_merge(Mod, OldConfig, NewConfig, Params) ->
     ?SAFE_CALL(Mod:on_config_merge(OldConfig, NewConfig, Params)).
 
+-spec call_config_to_file(module(), resource_config()) -> jsx:json_term().
+call_config_to_file(Mod, Config) ->
+    ?SAFE_CALL(Mod:on_config_to_file(Config)).
+
 -spec parse_config(resource_type(), binary() | term()) ->
     {ok, resource_config()} | {error, term()}.
 parse_config(ResourceType, RawConfig) when is_binary(RawConfig) ->
@@ -271,7 +279,7 @@ resource_type_from_str(ResourceType) ->
             false -> {error, {invalid_resource, Mod}}
         end
     catch error:badarg ->
-        {error, {resourec_not_found, ResourceType}}
+        {error, {resource_not_found, ResourceType}}
     end.
 
 call_instance(InstId, Query) ->
diff --git a/apps/emqx_resource/src/emqx_resource_api.erl b/apps/emqx_resource/src/emqx_resource_api.erl
index cc32d8a11..61d162ee6 100644
--- a/apps/emqx_resource/src/emqx_resource_api.erl
+++ b/apps/emqx_resource/src/emqx_resource_api.erl
@@ -34,7 +34,7 @@ get(Mod, #{id := Id}, _Params) ->
 
 put(Mod, #{id := Id}, Params) ->
     ConfigParams = proplists:get_value(<<"config">>, Params),
-    ResourceTypeStr = proplists:get_value(<<"resource_type">>, Params),
+    ResourceTypeStr = proplists:get_value(<<"resource_type">>, Params, #{}),
     case emqx_resource:resource_type_from_str(ResourceTypeStr) of
         {ok, ResourceType} ->
             do_put(Mod, stringnify(Id), ConfigParams, ResourceType, Params);
diff --git a/apps/emqx_resource/src/emqx_resource_instance.erl b/apps/emqx_resource/src/emqx_resource_instance.erl
index 3a750ebf3..ff7158c9c 100644
--- a/apps/emqx_resource/src/emqx_resource_instance.erl
+++ b/apps/emqx_resource/src/emqx_resource_instance.erl
@@ -110,8 +110,8 @@ load_config(RawConfig) when is_binary(RawConfig) ->
         Error -> Error
     end;
 
-load_config(#{<<"id">> := Id, <<"resource_type">> := ResourceTypeStr,
-              <<"config">> := MapConfig}) ->
+load_config(#{<<"id">> := Id, <<"resource_type">> := ResourceTypeStr} = Config) ->
+    MapConfig = maps:get(<<"config">>, Config, #{}),
     case emqx_resource:resource_type_from_str(ResourceTypeStr) of
         {ok, ResourceType} -> parse_and_load_config(Id, ResourceType, MapConfig);
         Error -> Error
@@ -130,8 +130,11 @@ create_local(InstId, ResourceType, InstConf) ->
     end.
 
 save_config_to_disk(InstId, ResourceType, Config) ->
+    %% TODO: send an event to the config handler, and the hander (single process)
+    %% will dump configs for all instances (from an ETS table) to a file.
     file:write_file(filename:join([emqx_data_dir(), binary_to_list(InstId) ++ ".conf"]),
-        jsx:encode(#{id => InstId, resource_type => ResourceType, config => Config})).
+        jsx:encode(#{id => InstId, resource_type => ResourceType,
+                     config => emqx_resource:call_config_to_file(Config)})).
 
 emqx_data_dir() ->
     "data".