diff --git a/apps/emqx_gateway/src/emqx_gateway_conf.erl b/apps/emqx_gateway/src/emqx_gateway_conf.erl
index cd1f64871..d2f6921e3 100644
--- a/apps/emqx_gateway/src/emqx_gateway_conf.erl
+++ b/apps/emqx_gateway/src/emqx_gateway_conf.erl
@@ -275,7 +275,7 @@ ret_gw(GwName, {ok, #{raw_config := GwConf}}) ->
                 end, maps:to_list(SubConf)),
             [NLConfs | Acc]
         end, [], maps:to_list(LsConf)),
-    {ok, maps:merge(GwConf1, #{<<"listeners">> => NLsConf})};
+    {ok, maps:merge(GwConf1, #{<<"listeners">> => lists:append(NLsConf)})};
 ret_gw(_GwName, Err) -> Err.
 
 ret_authn(GwName, {ok, #{raw_config := GwConf}}) ->
diff --git a/apps/emqx_gateway/src/emqx_gateway_utils.erl b/apps/emqx_gateway/src/emqx_gateway_utils.erl
index 95720ff13..cc771ed95 100644
--- a/apps/emqx_gateway/src/emqx_gateway_utils.erl
+++ b/apps/emqx_gateway/src/emqx_gateway_utils.erl
@@ -46,7 +46,6 @@
         ]).
 
 -export([ stringfy/1
-        , parse_address/1
         ]).
 
 -export([ normalize_config/1
@@ -332,19 +331,6 @@ stringfy(T) when is_list(T); is_binary(T) ->
 stringfy(T) ->
     iolist_to_binary(io_lib:format("~0p", [T])).
 
--spec parse_address(binary() | list()) -> {list(), integer()}.
-parse_address(S) when is_binary(S); is_list(S) ->
-    S1 = case is_binary(S) of
-            true -> lists:reverse(binary_to_list(S));
-             _ -> lists:reverse(S)
-         end,
-    case re:split(S1, ":", [{parts, 2}, {return, list}]) of
-        [Port0, Host0] ->
-            {lists:reverse(Host0), list_to_integer(lists:reverse(Port0))};
-        _ ->
-            error(badarg)
-    end.
-
 -spec normalize_config(emqx_config:config())
     -> list({ Type :: udp | tcp | ssl | dtls
             , Name :: atom()
diff --git a/apps/emqx_gateway/src/exproto/emqx_exproto_impl.erl b/apps/emqx_gateway/src/exproto/emqx_exproto_impl.erl
index 48dca4324..75057534f 100644
--- a/apps/emqx_gateway/src/exproto/emqx_exproto_impl.erl
+++ b/apps/emqx_gateway/src/exproto/emqx_exproto_impl.erl
@@ -148,13 +148,16 @@ stop_grpc_server(GwName) ->
 start_grpc_client_channel(_GwName, undefined) ->
     undefined;
 start_grpc_client_channel(GwName, Options = #{address := Address}) ->
-    {Host, Port} = try emqx_gateway_utils:parse_address(Address)
-                   catch error : badarg ->
-                         throw({badconf, #{key => address,
-                                           value => Address,
-                                           reason => illegal_grpc_address
-                                          }})
-                   end,
+    #{host := Host, port := Port} =
+        case emqx_http_lib:uri_parse(Address) of
+            {ok, URIMap0} -> URIMap0;
+            {error, _Reason} ->
+              throw({badconf, #{key => address,
+                                value => Address,
+                                reason => illegal_grpc_address
+                               }})
+
+        end,
     case maps:to_list(maps:get(ssl, Options, #{})) of
         [] ->
             SvrAddr = compose_http_uri(http, Host, Port),
@@ -170,7 +173,7 @@ start_grpc_client_channel(GwName, Options = #{address := Address}) ->
 compose_http_uri(Scheme, Host, Port) ->
     lists:flatten(
       io_lib:format(
-        "~s://~s:~w", [Scheme, Host, Port])).
+        "~s://~s:~w", [Scheme, inet:ntoa(Host), Port])).
 
 stop_grpc_client_channel(GwName) ->
     _ = grpc_client_sup:stop_channel_pool(GwName),
diff --git a/apps/emqx_gateway/src/lwm2m/emqx_lwm2m_impl.erl b/apps/emqx_gateway/src/lwm2m/emqx_lwm2m_impl.erl
index 47ed722b1..f4d73879d 100644
--- a/apps/emqx_gateway/src/lwm2m/emqx_lwm2m_impl.erl
+++ b/apps/emqx_gateway/src/lwm2m/emqx_lwm2m_impl.erl
@@ -92,7 +92,7 @@ on_gateway_update(Config, Gateway, GwState = #{ctx := Ctx}) ->
 
 on_gateway_unload(_Gateway = #{ name := GwName,
                                 config := Config
-                              }, _GwState = #{registry := RegPid}) ->
-    exit(RegPid, kill),
+                              }, _GwState = #{registry := _RegPid}) ->
+    _ = try emqx_lwm2m_xml_object_db:stop() catch _ : _  -> ok end,
     Listeners = emqx_gateway_utils:normalize_config(Config),
     emqx_gateway_utils:stop_listeners(GwName, Listeners).
diff --git a/apps/emqx_gateway/test/emqx_exproto_SUITE.erl b/apps/emqx_gateway/test/emqx_exproto_SUITE.erl
index 993ed4975..69e9afbaf 100644
--- a/apps/emqx_gateway/test/emqx_exproto_SUITE.erl
+++ b/apps/emqx_gateway/test/emqx_exproto_SUITE.erl
@@ -69,7 +69,7 @@ set_special_cfg(emqx_gateway) ->
     emqx_config:put(
       [gateway, exproto],
       #{server => #{bind => 9100},
-        handler => #{address => "127.0.0.1:9001"},
+        handler => #{address => "http://127.0.0.1:9001"},
         listeners => listener_confs(LisType)
        });
 set_special_cfg(_App) ->
diff --git a/apps/emqx_gateway/test/emqx_gateway_api_SUITE.erl b/apps/emqx_gateway/test/emqx_gateway_api_SUITE.erl
index f91347a6e..9b303c100 100644
--- a/apps/emqx_gateway/test/emqx_gateway_api_SUITE.erl
+++ b/apps/emqx_gateway/test/emqx_gateway_api_SUITE.erl
@@ -172,7 +172,7 @@ t_gateway_exproto(_) ->
     %% post
     GwConf = #{name => <<"exproto">>,
                server => #{bind => <<"9100">>},
-               handler => #{address => <<"127.0.0.1:9001">>},
+               handler => #{address => <<"http://127.0.0.1:9001">>},
                listeners => [
                   #{name => <<"def">>, type => <<"tcp">>, bind => <<"7993">>}
                 ]
diff --git a/apps/emqx_management/src/emqx_mgmt_api_app.erl b/apps/emqx_management/src/emqx_mgmt_api_app.erl
index 489d679be..4fa9ce469 100644
--- a/apps/emqx_management/src/emqx_mgmt_api_app.erl
+++ b/apps/emqx_management/src/emqx_mgmt_api_app.erl
@@ -139,13 +139,7 @@ api_key(post, #{body := App}) ->
         <<"desc">> := Desc0,
         <<"enable">> := Enable
     } = App,
-    %% undefined is never expired
-    ExpiredAt0 = maps:get(<<"expired_at">>, App, <<"undefined">>),
-    ExpiredAt =
-        case ExpiredAt0 of
-            <<"undefined">> -> undefined;
-            _ -> ExpiredAt0
-        end,
+    ExpiredAt = ensure_expired_at(App),
     Desc = unicode:characters_to_binary(Desc0, unicode),
     case emqx_mgmt_auth:create(Name, Enable, ExpiredAt, Desc) of
         {ok, NewApp} -> {200, format(NewApp)};
@@ -164,7 +158,7 @@ api_key_by_name(delete, #{bindings := #{name := Name}}) ->
     end;
 api_key_by_name(put, #{bindings := #{name := Name}, body := Body}) ->
     Enable = maps:get(<<"enable">>, Body, undefined),
-    ExpiredAt = maps:get(<<"expired_at">>, Body, undefined),
+    ExpiredAt = ensure_expired_at(Body),
     Desc = maps:get(<<"desc">>, Body, undefined),
     case emqx_mgmt_auth:update(Name, Enable, ExpiredAt, Desc) of
         {ok, App} -> {200, format(App)};
@@ -181,3 +175,6 @@ format(App = #{expired_at := ExpiredAt0, created_at := CreateAt}) ->
         expired_at => ExpiredAt,
         created_at => list_to_binary(calendar:system_time_to_rfc3339(CreateAt))
     }.
+
+ensure_expired_at(#{<<"expired_at">> := ExpiredAt})when is_integer(ExpiredAt) -> ExpiredAt;
+ensure_expired_at(_) -> undefined.
diff --git a/apps/emqx_management/src/emqx_mgmt_api_trace.erl b/apps/emqx_management/src/emqx_mgmt_api_trace.erl
index 52c0f0309..e03ae21eb 100644
--- a/apps/emqx_management/src/emqx_mgmt_api_trace.erl
+++ b/apps/emqx_management/src/emqx_mgmt_api_trace.erl
@@ -304,13 +304,16 @@ download_trace_log(get, #{bindings := #{name := Name}}) ->
             Zips = group_trace_file(ZipDir, TraceLog, TraceFiles),
             ZipFileName = ZipDir ++ binary_to_list(Name) ++ ".zip",
             {ok, ZipFile} = zip:zip(ZipFileName, Zips, [{cwd, ZipDir}]),
-            emqx_trace:delete_files_after_send(ZipFileName, Zips),
+            %% emqx_trace:delete_files_after_send(ZipFileName, Zips),
+            %% TODO use file replace file_binary.(delete file after send is not ready now).
+            {ok, Binary} = file:read_file(ZipFile),
+            ZipName = filename:basename(ZipFile),
+            _ = file:delete(ZipFile),
             Headers = #{
                 <<"content-type">> => <<"application/x-zip">>,
-                <<"content-disposition">> =>
-                iolist_to_binary("attachment; filename=" ++ filename:basename(ZipFile))
+                <<"content-disposition">> => iolist_to_binary("attachment; filename=" ++ ZipName)
             },
-            {200, Headers, {file, ZipFile}};
+            {200, Headers, {file_binary, ZipName, Binary}};
         {error, not_found} -> ?NOT_FOUND(Name)
     end.
 
diff --git a/apps/emqx_management/src/emqx_mgmt_auth.erl b/apps/emqx_management/src/emqx_mgmt_auth.erl
index 512ec6b0f..55201dc86 100644
--- a/apps/emqx_management/src/emqx_mgmt_auth.erl
+++ b/apps/emqx_management/src/emqx_mgmt_auth.erl
@@ -68,11 +68,11 @@ update(Name, Enable, ExpiredAt, Desc) ->
     Fun = fun() ->
         case mnesia:read(?APP, Name, write) of
             [] -> mnesia:abort(not_found);
-            [App0 = #?APP{enable = Enable0, expired_at = ExpiredAt0, desc = Desc0}] ->
+            [App0 = #?APP{enable = Enable0, desc = Desc0}] ->
                 App =
                     App0#?APP{
+                        expired_at = ExpiredAt,
                         enable = ensure_not_undefined(Enable, Enable0),
-                        expired_at = ensure_not_undefined(ExpiredAt, ExpiredAt0),
                         desc = ensure_not_undefined(Desc, Desc0)
                     },
                 ok = mnesia:write(App),
diff --git a/apps/emqx_management/test/emqx_mgmt_auth_api_SUITE.erl b/apps/emqx_management/test/emqx_mgmt_auth_api_SUITE.erl
index 73d4ad566..031e1622f 100644
--- a/apps/emqx_management/test/emqx_mgmt_auth_api_SUITE.erl
+++ b/apps/emqx_management/test/emqx_mgmt_auth_api_SUITE.erl
@@ -96,6 +96,13 @@ t_update(_Config) ->
     ?assertEqual(calendar:rfc3339_to_system_time(binary_to_list(ExpiredAt)),
         calendar:rfc3339_to_system_time(binary_to_list(maps:get(<<"expired_at">>, Update1)))
     ),
+    Unexpired1 = maps:without([expired_at], Change),
+    {ok, Update2} = update_app(Name, Unexpired1),
+    ?assertEqual(<<"undefined">>, maps:get(<<"expired_at">>, Update2)),
+    Unexpired2 = Change#{expired_at => <<"undefined">>},
+    {ok, Update3} = update_app(Name, Unexpired2),
+    ?assertEqual(<<"undefined">>, maps:get(<<"expired_at">>, Update3)),
+
     ?assertEqual({error, {"HTTP/1.1", 404, "Not Found"}}, update_app(<<"Not-Exist">>, Change)),
     ok.
 
@@ -137,6 +144,10 @@ t_authorize(_Config) ->
     },
     ?assertMatch({ok, #{<<"api_key">> := _, <<"enable">> := true}}, update_app(Name, Expired)),
     ?assertEqual(Unauthorized, emqx_mgmt_api_test_util:request_api(get, BanPath, BasicHeader)),
+    UnExpired = #{expired_at => undefined},
+    ?assertMatch({ok, #{<<"api_key">> := _, <<"expired_at">> := <<"undefined">>}},
+        update_app(Name, UnExpired)),
+    {ok, _Status1} = emqx_mgmt_api_test_util:request_api(get, BanPath, BasicHeader),
     ok.
 
 t_create_unexpired_app(_Config) ->
diff --git a/apps/emqx_retainer/README.md b/apps/emqx_retainer/README.md
index 84d777bbc..b3065fa9c 100644
--- a/apps/emqx_retainer/README.md
+++ b/apps/emqx_retainer/README.md
@@ -13,10 +13,9 @@ etc/emqx_retainer.conf:
 ## Where to store the retained messages.
 ## Notice that all nodes in a cluster are to have the same storage_type.
 ##
-## Value: ram | disc | disc_only
+## Value: ram | disc
 ##  - ram: memory only
 ##  - disc: both memory and disc
-##  - disc_only: disc only
 ##
 ## Default: ram
 retainer.storage_type = ram
@@ -56,4 +55,3 @@ Author
 ------
 
 EMQ X Team
-
diff --git a/apps/emqx_retainer/etc/emqx_retainer.conf b/apps/emqx_retainer/etc/emqx_retainer.conf
index 92dc62f24..5824186d0 100644
--- a/apps/emqx_retainer/etc/emqx_retainer.conf
+++ b/apps/emqx_retainer/etc/emqx_retainer.conf
@@ -74,7 +74,7 @@ emqx_retainer {
 
     type = built_in_database
 
-    ## storage_type: ram | disc | disc_only
+    ## storage_type: ram | disc
     storage_type = ram
 
     ## Maximum number of retained messages. 0 means no limit.
diff --git a/apps/emqx_retainer/src/emqx_retainer_mnesia.erl b/apps/emqx_retainer/src/emqx_retainer_mnesia.erl
index eb08bf6cc..afea2a4b0 100644
--- a/apps/emqx_retainer/src/emqx_retainer_mnesia.erl
+++ b/apps/emqx_retainer/src/emqx_retainer_mnesia.erl
@@ -45,24 +45,22 @@
 create_resource(#{storage_type := StorageType}) ->
     Copies = case StorageType of
                  ram       -> ram_copies;
-                 disc      -> disc_copies;
-                 disc_only -> disc_only_copies
+                 disc      -> disc_copies
              end,
-    TableType = case StorageType of
-                    disc_only -> set;
-                    _ -> ordered_set
-                end,
+
     StoreProps = [{ets, [compressed,
                          {read_concurrency, true},
                          {write_concurrency, true}]},
                   {dets, [{auto_save, 1000}]}],
+
     ok = mria:create_table(?TAB, [
-                {type, TableType},
-                {rlog_shard, ?RETAINER_SHARD},
-                {storage, Copies},
-                {record_name, retained},
-                {attributes, record_info(fields, retained)},
-                {storage_properties, StoreProps}]),
+                                  {type, ordered_set},
+                                  {rlog_shard, ?RETAINER_SHARD},
+                                  {storage, Copies},
+                                  {record_name, retained},
+                                  {attributes, record_info(fields, retained)},
+                                  {storage_properties, StoreProps}
+                                 ]),
     ok = mria_rlog:wait_for_shards([?RETAINER_SHARD], infinity),
     case mnesia:table_info(?TAB, storage_type) of
         Copies -> ok;
diff --git a/apps/emqx_retainer/src/emqx_retainer_schema.erl b/apps/emqx_retainer/src/emqx_retainer_schema.erl
index e1fa8373a..d6bc598a7 100644
--- a/apps/emqx_retainer/src/emqx_retainer_schema.erl
+++ b/apps/emqx_retainer/src/emqx_retainer_schema.erl
@@ -20,7 +20,7 @@ fields("emqx_retainer") ->
 
 fields(mnesia_config) ->
     [ {type, ?TYPE(hoconsc:union([built_in_database]))}
-    , {storage_type, sc(hoconsc:union([ram, disc, disc_only]), ram)}
+    , {storage_type, sc(hoconsc:union([ram, disc]), ram)}
     , {max_retained_messages, sc(integer(), 0, fun is_pos_integer/1)}
     ];
 
diff --git a/apps/emqx_statsd/src/emqx_statsd_api.erl b/apps/emqx_statsd/src/emqx_statsd_api.erl
index d545003b0..ab9416266 100644
--- a/apps/emqx_statsd/src/emqx_statsd_api.erl
+++ b/apps/emqx_statsd/src/emqx_statsd_api.erl
@@ -59,10 +59,12 @@ statsd(put, #{body := Body}) ->
                             Body,
                             #{rawconf_with_defaults => true, override_to => cluster}) of
         {ok, #{raw_config := NewConfig, config := Config}} ->
-            _ = emqx_statsd_sup:stop_child(?APP),
+            ok = emqx_statsd_sup:ensure_child_stopped(?APP),
             case maps:get(<<"enable">>, Body) of
-                true -> emqx_statsd_sup:start_child(?APP, maps:get(config, Config));
-                false -> ok
+                true ->
+                    ok = emqx_statsd_sup:ensure_child_started(?APP, maps:get(config, Config));
+                false ->
+                    ok
             end,
             {200, NewConfig};
         {error, Reason} ->
diff --git a/apps/emqx_statsd/src/emqx_statsd_app.erl b/apps/emqx_statsd/src/emqx_statsd_app.erl
index 820a86c04..c0a17fc5b 100644
--- a/apps/emqx_statsd/src/emqx_statsd_app.erl
+++ b/apps/emqx_statsd/src/emqx_statsd_app.erl
@@ -34,7 +34,7 @@ stop(_) ->
 maybe_enable_statsd() ->
     case emqx_conf:get([statsd, enable], false) of
         true ->
-            emqx_statsd_sup:start_child(?APP, emqx_conf:get([statsd], #{}));
+            emqx_statsd_sup:ensure_child_started(?APP, emqx_conf:get([statsd], #{}));
         false ->
             ok
     end.
diff --git a/apps/emqx_statsd/src/emqx_statsd_sup.erl b/apps/emqx_statsd/src/emqx_statsd_sup.erl
index 02b50e3ca..983cf97d4 100644
--- a/apps/emqx_statsd/src/emqx_statsd_sup.erl
+++ b/apps/emqx_statsd/src/emqx_statsd_sup.erl
@@ -8,9 +8,9 @@
 -behaviour(supervisor).
 
 -export([ start_link/0
-        , start_child/1
-        , start_child/2
-        , stop_child/1
+        , ensure_child_started/1
+        , ensure_child_started/2
+        , ensure_child_stopped/1
         ]).
 
 -export([init/1]).
@@ -26,19 +26,24 @@
 start_link() ->
     supervisor:start_link({local, ?MODULE}, ?MODULE, []).
 
--spec start_child(supervisor:child_spec()) -> ok.
-start_child(ChildSpec) when is_map(ChildSpec) ->
+-spec ensure_child_started(supervisor:child_spec()) -> ok.
+ensure_child_started(ChildSpec) when is_map(ChildSpec) ->
     assert_started(supervisor:start_child(?MODULE, ChildSpec)).
 
--spec start_child(atom(), map()) -> ok.
-start_child(Mod, Opts) when is_atom(Mod) andalso is_map(Opts) ->
+-spec ensure_child_started(atom(), map()) -> ok.
+ensure_child_started(Mod, Opts) when is_atom(Mod) andalso is_map(Opts) ->
     assert_started(supervisor:start_child(?MODULE, ?CHILD(Mod, Opts))).
 
--spec(stop_child(any()) -> ok | {error, term()}).
-stop_child(ChildId) ->
+%% @doc Stop the child worker process.
+-spec ensure_child_stopped(any()) -> ok.
+ensure_child_stopped(ChildId) ->
     case supervisor:terminate_child(?MODULE, ChildId) of
-        ok -> supervisor:delete_child(?MODULE, ChildId);
-        Error -> Error
+        ok ->
+            %% with terminate_child/2 returned 'ok', it's not possible
+            %% for supervisor:delete_child/2 to return {error, Reason}
+            ok = supervisor:delete_child(?MODULE, ChildId);
+        {error, not_found} ->
+            ok
     end.
 
 init([]) ->
@@ -50,5 +55,5 @@ init([]) ->
 
 assert_started({ok, _Pid}) -> ok;
 assert_started({ok, _Pid, _Info}) -> ok;
-assert_started({error, {already_tarted, _Pid}}) -> ok;
+assert_started({error, {already_started, _Pid}}) -> ok;
 assert_started({error, Reason}) -> erlang:error(Reason).