diff --git a/apps/iot/include/iot.hrl b/apps/iot/include/iot.hrl
index e594496..fba356f 100644
--- a/apps/iot/include/iot.hrl
+++ b/apps/iot/include/iot.hrl
@@ -11,11 +11,12 @@
 %% 主机是否在线
 -define(HOST_OFFLINE, 0).
 -define(HOST_ONLINE, 1).
+-define(HOST_NOT_JOINED, -1).
 
 %% 设备是否在线状态
 -define(DEVICE_OFFLINE, 0).
 -define(DEVICE_ONLINE, 1).
--define(DEVICE_UNKNOWN, 2).
+-define(DEVICE_NOT_JOINED, -1).
 
 %% 下发的任务状态
 -define(TASK_STATUS_INIT,   -1).  %% 未接入
diff --git a/apps/iot/src/database/device_bo.erl b/apps/iot/src/database/device_bo.erl
index 1fa657b..40875ac 100644
--- a/apps/iot/src/database/device_bo.erl
+++ b/apps/iot/src/database/device_bo.erl
@@ -32,11 +32,23 @@ get_device_by_uuid(DeviceUUID) when is_binary(DeviceUUID) ->
 
 %% 修改主机的状态
 -spec change_status(DeviceUUID :: binary(), Status :: integer()) -> {ok, AffectedRows :: integer()} | {error, Reason :: any()}.
-change_status(DeviceUUID, Status) when is_binary(DeviceUUID), is_integer(Status) ->
-    case mysql_pool:update_by(mysql_iot, <<"UPDATE device SET status = ? WHERE device_uuid = ? LIMIT 1">>, [Status, DeviceUUID]) of
+change_status(DeviceUUID, NStatus) when is_binary(DeviceUUID), is_integer(NStatus) ->
+    case change_status0(DeviceUUID, NStatus) of
         Result = {ok, _} ->
-            event_logs_bo:insert(?EVENT_DEVICE, DeviceUUID, Status),
+            event_logs_bo:insert(?EVENT_DEVICE, DeviceUUID, NStatus),
             Result;
         Error ->
             Error
-    end.
\ No newline at end of file
+    end.
+change_status0(DeviceUUID, ?DEVICE_ONLINE) when is_binary(DeviceUUID) ->
+    Timestamp = calendar:local_time(),
+    case mysql_pool:get_row(mysql_iot, <<"SELECT status FROM device WHERE device_uuid = ? LIMIT 1">>, [DeviceUUID]) of
+        {ok, #{<<"status">> := -1}} ->
+            mysql_pool:update_by(mysql_iot, <<"UPDATE device SET status = ?, access_at = ?, updated_at = ? WHERE device_uuid = ? LIMIT 1">>, [?DEVICE_ONLINE, Timestamp, Timestamp, DeviceUUID]);
+        {ok, _} ->
+            mysql_pool:update_by(mysql_iot, <<"UPDATE device SET status = ?, updated_at = ? WHERE device_uuid = ? LIMIT 1">>, [?DEVICE_ONLINE, Timestamp, DeviceUUID]);
+        undefined ->
+            {error, <<"device not found">>}
+    end;
+change_status0(DeviceUUID, ?DEVICE_OFFLINE) when is_binary(DeviceUUID) ->
+    mysql_pool:update_by(mysql_iot, <<"UPDATE device SET status = ? WHERE device_uuid = ? LIMIT 1">>, [?DEVICE_OFFLINE, DeviceUUID]).
\ No newline at end of file
diff --git a/apps/iot/src/database/host_bo.erl b/apps/iot/src/database/host_bo.erl
index 2d1cce3..bb4b2b0 100644
--- a/apps/iot/src/database/host_bo.erl
+++ b/apps/iot/src/database/host_bo.erl
@@ -32,11 +32,24 @@ get_host_by_id(HostId) when is_integer(HostId) ->
 
 %% 修改主机的状态
 -spec change_status(UUID :: binary(), Status :: integer()) -> {ok, AffectedRows :: integer()} | {error, Reason :: any()}.
-change_status(UUID, Status) when is_binary(UUID), is_integer(Status) ->
-   case mysql_pool:update_by(mysql_iot, <<"UPDATE host SET status = ? WHERE uuid = ? LIMIT 1">>, [Status, UUID]) of
-       Result = {ok, _} ->
-           event_logs_bo:insert(?EVENT_HOST, UUID, Status),
-           Result;
-       Error ->
-           Error
-   end.
+change_status(UUID, NStatus) when is_binary(UUID), is_integer(NStatus) ->
+    case change_status0(UUID, NStatus) of
+        Result = {ok, _} ->
+            event_logs_bo:insert(?EVENT_HOST, UUID, NStatus),
+            Result;
+        Error ->
+            Error
+    end.
+change_status0(UUID, ?HOST_ONLINE) when is_binary(UUID) ->
+    Timestamp = calendar:local_time(),
+    case mysql_pool:get_row(mysql_iot, <<"SELECT status FROM host WHERE uuid = ? LIMIT 1">>, [UUID]) of
+        %% 第一次更新激活
+        {ok, #{<<"status">> := -1}} ->
+            mysql_pool:update_by(mysql_iot, <<"UPDATE host SET status = ?, access_at = ?, updated_at = ? WHERE uuid = ? LIMIT 1">>, [?HOST_ONLINE, Timestamp, Timestamp, UUID]);
+        {ok, _} ->
+            mysql_pool:update_by(mysql_iot, <<"UPDATE host SET status = ?, updated_at = ? WHERE uuid = ? LIMIT 1">>, [?HOST_ONLINE, Timestamp, UUID]);
+        undefined ->
+            {error, <<"host not found">>}
+    end;
+change_status0(UUID, ?HOST_OFFLINE) when is_binary(UUID) ->
+    mysql_pool:update_by(mysql_iot, <<"UPDATE host SET status = ? WHERE uuid = ? LIMIT 1">>, [?HOST_OFFLINE, UUID]).
\ No newline at end of file
diff --git a/apps/iot/src/iot_database_buffer.erl b/apps/iot/src/iot_database_buffer.erl
new file mode 100644
index 0000000..fc1cdff
--- /dev/null
+++ b/apps/iot/src/iot_database_buffer.erl
@@ -0,0 +1,109 @@
+%%%-------------------------------------------------------------------
+%%% @author aresei
+%%% @copyright (C) 2023, <COMPANY>
+%%% @doc
+%%%
+%%% @end
+%%% Created : 25. 9月 2023 10:05
+%%%-------------------------------------------------------------------
+-module(iot_database_buffer).
+-author("aresei").
+
+-behaviour(gen_server).
+
+%% API
+-export([start_link/0]).
+-export([find_device/1]).
+
+%% gen_server callbacks
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
+
+-define(SERVER, ?MODULE).
+
+-record(state, {
+    devices_map = #{} :: map()
+}).
+
+%%%===================================================================
+%%% API
+%%%===================================================================
+
+-spec find_device(DeviceUUID :: binary()) -> error | {ok, Device :: map()}.
+find_device(DeviceUUID) when is_binary(DeviceUUID) ->
+    gen_server:call(?MODULE, {find_device, DeviceUUID}).
+
+%% @doc Spawns the server and registers the local name (unique)
+-spec(start_link() ->
+    {ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
+start_link() ->
+    gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
+
+%%%===================================================================
+%%% gen_server callbacks
+%%%===================================================================
+
+%% @private
+%% @doc Initializes the server
+-spec(init(Args :: term()) ->
+    {ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} |
+    {stop, Reason :: term()} | ignore).
+init([]) ->
+    {ok, Devices} = device_bo:get_all_devices(),
+    DevicesMap = maps:from_list(lists:map(fun(Device = #{<<"device_uuid">> := DeviceUUID}) -> {DeviceUUID, Device} end, Devices)),
+
+    erlang:start_timer(300 * 1000, self(), clean_up),
+
+    {ok, #state{devices_map = DevicesMap}}.
+
+%% @private
+%% @doc Handling call messages
+-spec(handle_call(Request :: term(), From :: {pid(), Tag :: term()},
+    State :: #state{}) ->
+    {reply, Reply :: term(), NewState :: #state{}} |
+    {reply, Reply :: term(), NewState :: #state{}, timeout() | hibernate} |
+    {noreply, NewState :: #state{}} |
+    {noreply, NewState :: #state{}, timeout() | hibernate} |
+    {stop, Reason :: term(), Reply :: term(), NewState :: #state{}} |
+    {stop, Reason :: term(), NewState :: #state{}}).
+handle_call({find_device, DeviceUUID}, _From, State = #state{devices_map = DevicesMap}) ->
+    {reply, maps:find(DeviceUUID, DevicesMap), State}.
+
+%% @private
+%% @doc Handling cast messages
+-spec(handle_cast(Request :: term(), State :: #state{}) ->
+    {noreply, NewState :: #state{}} |
+    {noreply, NewState :: #state{}, timeout() | hibernate} |
+    {stop, Reason :: term(), NewState :: #state{}}).
+handle_cast(_Request, State = #state{}) ->
+    {noreply, State}.
+
+%% @private
+%% @doc Handling all non call/cast messages
+-spec(handle_info(Info :: timeout() | term(), State :: #state{}) ->
+    {noreply, NewState :: #state{}} |
+    {noreply, NewState :: #state{}, timeout() | hibernate} |
+    {stop, Reason :: term(), NewState :: #state{}}).
+handle_info({timeout, _, clean_up}, State = #state{}) ->
+    {noreply, State#state{devices_map = #{}}}.
+
+%% @private
+%% @doc This function is called by a gen_server when it is about to
+%% terminate. It should be the opposite of Module:init/1 and do any
+%% necessary cleaning up. When it returns, the gen_server terminates
+%% with Reason. The return value is ignored.
+-spec(terminate(Reason :: (normal | shutdown | {shutdown, term()} | term()),
+    State :: #state{}) -> term()).
+terminate(_Reason, _State = #state{}) ->
+    ok.
+
+%% @private
+%% @doc Convert process state when code is changed
+-spec(code_change(OldVsn :: term() | {down, term()}, State :: #state{},
+    Extra :: term()) ->
+    {ok, NewState :: #state{}} | {error, Reason :: term()}).
+code_change(_OldVsn, State = #state{}, _Extra) ->
+    {ok, State}.
+
+%%%===================================================================
+%%% Internal functions
+%%%===================================================================
diff --git a/apps/iot/src/iot_device.erl b/apps/iot/src/iot_device.erl
index 1b04ae0..774ddb9 100644
--- a/apps/iot/src/iot_device.erl
+++ b/apps/iot/src/iot_device.erl
@@ -78,8 +78,25 @@ start_link(Name, DeviceUUID) when is_atom(Name), is_binary(DeviceUUID) ->
 %% gen_statem:start_link/[3,4], this function is called by the new
 %% process to initialize.
 init([DeviceUUID]) when is_binary(DeviceUUID) ->
-    gen_server:cast(self(), reload),
-    {ok, ?STATE_DENIED, #state{device_uuid = DeviceUUID}}.
+    DeviceInfo1 = case iot_database_buffer:find_device(DeviceUUID) of
+                      error ->
+                          device_bo:get_device_by_uuid(DeviceUUID);
+                      {ok, DeviceInfo} ->
+                          {ok, DeviceInfo}
+                  end,
+
+    case DeviceInfo1 of
+        {ok, #{<<"authorize_status">> := AuthorizeStatus, <<"status">> := Status}} ->
+            case AuthorizeStatus =:= ?DEVICE_AUTH_AUTHED of
+                true ->
+                    {ok, ?STATE_ACTIVATED, #state{device_uuid = DeviceUUID, status = Status}};
+                false ->
+                    {ok, ?STATE_DENIED, #state{device_uuid = DeviceUUID, status = Status}}
+            end;
+        undefined ->
+            lager:warning("[iot_device] device uuid: ~p, loaded from mysql failed", [DeviceUUID]),
+            ignore
+    end.
 
 %% @private
 %% @doc This function is called by a gen_statem when it needs to find out
@@ -97,13 +114,28 @@ handle_event({call, From}, is_activated, StateName, State = #state{}) ->
     {keep_state, State, [{reply, From, StateName =:= ?STATE_ACTIVATED}]};
 
 %% 改变为在线状态，但是数据库中的状态已经是在线状态，忽略
-handle_event(cast, {change_status, ?DEVICE_ONLINE}, ?STATE_ACTIVATED, State = #state{status = ?DEVICE_ONLINE}) ->
+handle_event(cast, {change_status, ?DEVICE_ONLINE}, _, State = #state{status = ?DEVICE_ONLINE}) ->
     {keep_state, State};
 %% 改变数据库的状态, 其他情况下执行次数都很少
-handle_event(cast, {change_status, NewStatus}, _, State = #state{device_uuid = DeviceUUID}) ->
-    {ok, _} = device_bo:change_status(DeviceUUID, NewStatus),
-    report_event(DeviceUUID, NewStatus),
-    {keep_state, State#state{status = NewStatus}};
+handle_event(cast, {change_status, ?DEVICE_ONLINE}, _, State = #state{device_uuid = DeviceUUID}) ->
+    {ok, _} = device_bo:change_status(DeviceUUID, ?DEVICE_ONLINE),
+    report_event(DeviceUUID, ?DEVICE_ONLINE),
+    {keep_state, State#state{status = ?DEVICE_ONLINE}};
+
+handle_event(cast, {change_status, ?DEVICE_OFFLINE}, _, State = #state{device_uuid = DeviceUUID}) ->
+    {ok, #{<<"status">> := Status}} = device_bo:get_device_by_uuid(DeviceUUID),
+    case Status of
+        ?DEVICE_NOT_JOINED ->
+            lager:debug("[iot_device] device: ~p, device_maybe_offline, not joined, can not change to offline", [DeviceUUID]),
+            {keep_state, State#state{status = ?DEVICE_NOT_JOINED}};
+        ?DEVICE_OFFLINE ->
+            lager:debug("[iot_device] device: ~p, device_maybe_offline, is offline, do nothing", [DeviceUUID]),
+            {keep_state, State#state{status = ?DEVICE_OFFLINE}};
+        ?DEVICE_ONLINE ->
+            {ok, _} = device_bo:change_status(DeviceUUID, ?DEVICE_OFFLINE),
+            report_event(DeviceUUID, ?DEVICE_OFFLINE),
+            {keep_state, State#state{status = ?DEVICE_OFFLINE}}
+    end;
 
 %% 重新加载数据库数据
 handle_event(cast, reload, _, State = #state{device_uuid = DeviceUUID}) ->
@@ -114,8 +146,7 @@ handle_event(cast, reload, _, State = #state{device_uuid = DeviceUUID}) ->
                 true ->
                     {next_state, ?STATE_ACTIVATED, State#state{status = Status}};
                 false ->
-                    {ok, _} = device_bo:change_status(DeviceUUID, ?DEVICE_OFFLINE),
-                    {next_state, ?STATE_DENIED, State#state{status = ?DEVICE_OFFLINE}}
+                    {next_state, ?STATE_DENIED, State#state{status = Status}}
             end;
         undefined ->
             lager:warning("[iot_device] device uuid: ~p, loaded from mysql failed", [DeviceUUID]),
@@ -133,8 +164,7 @@ handle_event(cast, {auth, Auth}, StateName, State = #state{device_uuid = DeviceU
 
         {?STATE_ACTIVATED, false} ->
             lager:debug("[iot_device] device_uuid: ~p, auth: false, state_name from: ~p, to: ~p", [DeviceUUID, ?STATE_ACTIVATED, ?STATE_DENIED]),
-            {ok, _} = device_bo:change_status(DeviceUUID, ?DEVICE_OFFLINE),
-            {next_state, ?STATE_DENIED, State#state{status = ?DEVICE_OFFLINE}};
+            {next_state, ?STATE_DENIED, State};
         {?STATE_ACTIVATED, true} ->
             lager:debug("[iot_device] device_uuid: ~p, auth: true, will keep state_name: ~p", [DeviceUUID, ?STATE_ACTIVATED]),
             {keep_state, State}
@@ -159,19 +189,21 @@ code_change(_OldVsn, StateName, State = #state{}, _Extra) ->
 %%%===================================================================
 
 -spec report_event(DeviceUUID :: binary(), NewStatus :: integer()) -> no_return().
-report_event(DeviceUUID, ?DEVICE_UNKNOWN) ->
-    lager:notice("[iot_device] device_uuid: ~p, status: unknown, not report", [DeviceUUID]),
-    ok;
 report_event(DeviceUUID, NewStatus) when is_binary(DeviceUUID), is_integer(NewStatus) ->
+    TextMap = #{
+        0 => <<"离线"/utf8>>,
+        1 => <<"在线"/utf8>>
+    },
     %% 设备的状态信息上报给中电
     Timestamp = iot_util:timestamp_of_seconds(),
     FieldsList = [#{
         <<"key">> => <<"device_status">>,
         <<"value">> => NewStatus,
+        <<"value_text">> => maps:get(NewStatus, TextMap),
         <<"unit">> => 0,
         <<"type">> => <<"DI">>,
         <<"name">> => <<"设备状态"/utf8>>,
         <<"timestamp">> => Timestamp
     }],
     iot_router:route_uuid(DeviceUUID, FieldsList, Timestamp),
-    lager:debug("[iot_host] device_uuid: ~p, route fields: ~p", [DeviceUUID, FieldsList]).
\ No newline at end of file
+    lager:debug("[iot_device] device_uuid: ~p, route fields: ~p", [DeviceUUID, FieldsList]).
\ No newline at end of file
diff --git a/apps/iot/src/iot_device_sup.erl b/apps/iot/src/iot_device_sup.erl
index 7f41d66..c7dc12d 100644
--- a/apps/iot/src/iot_device_sup.erl
+++ b/apps/iot/src/iot_device_sup.erl
@@ -35,7 +35,8 @@ ensured_device_started(DeviceUUID) when is_binary(DeviceUUID) ->
 
 delete_device(UUID) when is_binary(UUID) ->
     Id = iot_device:get_name(UUID),
-    supervisor:terminate_child(?MODULE, Id).
+    ok = supervisor:terminate_child(?MODULE, Id),
+    supervisor:delete_child(?MODULE, Id).
 
 child_spec(DeviceUUID) when is_binary(DeviceUUID) ->
     Name = iot_device:get_name(DeviceUUID),
diff --git a/apps/iot/src/iot_host.erl b/apps/iot/src/iot_host.erl
index b99e8e2..acad4e2 100644
--- a/apps/iot/src/iot_host.erl
+++ b/apps/iot/src/iot_host.erl
@@ -4,17 +4,21 @@
 %%% @doc
 %%%
 %%% @end
-%%% Created : 19. 6月 2023 10:32
+%%% Created : 22. 9月 2023 16:38
 %%%-------------------------------------------------------------------
 -module(iot_host).
 -author("aresei").
 -include("iot.hrl").
 
--behaviour(gen_server).
+-behaviour(gen_statem).
 
 %% 心跳包检测时间间隔, 15分钟检测一次
 -define(HEARTBEAT_INTERVAL, 900 * 1000).
 
+%% 状态
+-define(STATE_DENIED, denied).
+-define(STATE_ACTIVATED, activated).
+
 %% API
 -export([start_link/2, get_name/1, get_alias_name/1, get_pid/1, handle/2, activate/2]).
 -export([get_metric/1, publish_message/4, get_aes/1, get_status/1]).
@@ -22,15 +26,13 @@
 -export([reload_device/2, delete_device/2, activate_device/3]).
 -export([heartbeat/1]).
 
-%% gen_server callbacks
--export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
+%% gen_statem callbacks
+-export([init/1, handle_event/4, terminate/3, code_change/4, callback_mode/0]).
 
 -record(state, {
     host_id :: integer(),
     %% 从数据库里面读取到的数据
     uuid :: binary(),
-    %% 记录最后的状态信息
-    last_status :: integer(),
     %% aes的key, 后续通讯需要基于这个加密
     aes = <<>> :: binary(),
     has_session = false :: boolean(),
@@ -45,7 +47,6 @@
 %%%===================================================================
 %%% API
 %%%===================================================================
-
 -spec get_pid(UUID :: binary()) -> undefined | pid().
 get_pid(UUID) when is_binary(UUID) ->
     Name = get_name(UUID),
@@ -63,38 +64,38 @@ get_alias_name(HostId0) when is_integer(HostId0) ->
 %% 处理消息
 -spec handle(Pid :: pid(), Packet :: {atom(), binary()} | {atom(), {binary(), binary()}}) -> no_return().
 handle(Pid, Packet) when is_pid(Pid) ->
-    gen_server:cast(Pid, {handle, Packet}).
+    gen_statem:cast(Pid, {handle, Packet}).
 
 -spec get_aes(Pid :: pid()) -> {ok, Aes :: binary()}.
 get_aes(Pid) when is_pid(Pid) ->
-    gen_server:call(Pid, get_aes).
+    gen_statem:call(Pid, get_aes).
 
 -spec get_status(Pid :: pid()) -> {ok, Status :: map()}.
 get_status(Pid) when is_pid(Pid) ->
-    gen_server:call(Pid, get_status).
+    gen_statem:call(Pid, get_status).
 
 %% 激活主机, true 表示激活； false表示关闭激活
 -spec activate(Pid :: pid(), Auth :: boolean()) -> ok.
 activate(Pid, Auth) when is_pid(Pid), is_boolean(Auth) ->
-    gen_server:call(Pid, {activate, Auth}).
+    gen_statem:call(Pid, {activate, Auth}).
 
 -spec get_metric(Pid :: pid()) -> {ok, MetricInfo :: map()}.
 get_metric(Pid) when is_pid(Pid) ->
-    gen_server:call(Pid, get_metric).
+    gen_statem:call(Pid, get_metric).
 
 -spec attach_channel(pid(), pid()) -> ok | {error, Reason :: binary()}.
 attach_channel(Pid, ChannelPid) when is_pid(Pid), is_pid(ChannelPid) ->
-    gen_server:call(Pid, {attach_channel, ChannelPid}).
+    gen_statem:call(Pid, {attach_channel, ChannelPid}).
 
 -spec create_session(Pid :: pid(), PubKey :: binary()) -> {ok, Reply :: binary()}.
 create_session(Pid, PubKey) when is_pid(Pid), is_binary(PubKey) ->
-    gen_server:call(Pid, {create_session, PubKey}).
+    gen_statem:call(Pid, {create_session, PubKey}).
 
 %% 这里占用的的调用进程的时间
 -spec publish_message(Pid :: pid(), CommandType :: integer(), Params :: binary() | {Encrypt :: atom(), Params :: binary()}, Timeout :: integer()) ->
     ok | {ok, Response :: binary()} | {error, Reason :: any()}.
 publish_message(Pid, CommandType, Params, Timeout) when is_pid(Pid), is_integer(CommandType), is_integer(Timeout) ->
-    case gen_server:call(Pid, {publish_message, self(), CommandType, Params}) of
+    case gen_statem:call(Pid, {publish_message, self(), CommandType, Params}) of
         {ok, Ref} ->
             receive
                 {ws_response, Ref} ->
@@ -112,247 +113,227 @@ publish_message(Pid, CommandType, Params, Timeout) when is_pid(Pid), is_integer(
 
 -spec reload_device(Pid :: pid(), DeviceUUID :: binary()) -> ok | {error, Reason :: any()}.
 reload_device(Pid, DeviceUUID) when is_pid(Pid), is_binary(DeviceUUID) ->
-    gen_server:call(Pid, {reload_device, DeviceUUID}).
+    gen_statem:call(Pid, {reload_device, DeviceUUID}).
 
 -spec delete_device(Pid :: pid(), DeviceUUID :: binary()) -> ok.
 delete_device(Pid, DeviceUUID) when is_pid(Pid), is_binary(DeviceUUID) ->
-    gen_server:call(Pid, {delete_device, DeviceUUID}).
+    gen_statem:call(Pid, {delete_device, DeviceUUID}).
 
 -spec activate_device(Pid :: pid(), DeviceUUID :: binary(), Auth :: boolean()) -> ok | {error, Reason :: any()}.
 activate_device(Pid, DeviceUUID, Auth) when is_pid(Pid), is_binary(DeviceUUID), is_boolean(Auth) ->
-    gen_server:call(Pid, {activate_device, DeviceUUID, Auth}).
+    gen_statem:call(Pid, {activate_device, DeviceUUID, Auth}).
 
 -spec heartbeat(Pid :: pid()) -> no_return().
 heartbeat(undefined) ->
     ok;
 heartbeat(Pid) when is_pid(Pid) ->
-    gen_server:cast(Pid, heartbeat).
+    gen_statem:cast(Pid, heartbeat).
 
 %% @doc Creates a gen_statem process which calls Module:init/1 to
 %% initialize. To ensure a synchronized start-up procedure, this
 %% function does not return until Module:init/1 has returned.
 start_link(Name, UUID) when is_atom(Name), is_binary(UUID) ->
-    gen_server:start_link({local, Name}, ?MODULE, [UUID], []).
+    gen_statem:start_link({local, Name}, ?MODULE, [UUID], []).
 
 %%%===================================================================
 %%% gen_statem callbacks
 %%%===================================================================
 
 %% @private
-%% @doc Initializes the server
--spec(init(Args :: term()) ->
-    {ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} |
-    {stop, Reason :: term()} | ignore).
+%% @doc Whenever a gen_statem is started using gen_statem:start/[3,4] or
+%% gen_statem:start_link/[3,4], this function is called by the new
+%% process to initialize.
 init([UUID]) ->
-    host_bo:change_status(UUID, ?HOST_OFFLINE),
-    report_event(UUID, ?HOST_OFFLINE),
-
     case host_bo:get_host_by_uuid(UUID) of
-        {ok, #{<<"id">> := HostId}} ->
+        {ok, #{<<"id">> := HostId, <<"authorize_status">> := AuthorizeStatus}} ->
             %% 通过host_id注册别名, 可以避免通过查询数据库获取HostPid
             AliasName = get_alias_name(HostId),
             global:register_name(AliasName, self()),
             Aes = list_to_binary(iot_util:rand_bytes(32)),
 
+            %% 心跳检测机制
+            erlang:start_timer(?HEARTBEAT_INTERVAL, self(), heartbeat_ticker),
+
             %% 启动主机相关的devices
             {ok, Devices} = device_bo:get_host_devices(HostId),
             lists:foreach(fun iot_device_sup:ensured_device_started/1, Devices),
 
-            %% 心跳检测机制
-            erlang:start_timer(?HEARTBEAT_INTERVAL, self(), heartbeat_ticker),
-
-            {ok, #state{host_id = HostId, uuid = UUID, last_status = ?HOST_OFFLINE, aes = Aes, has_session = false}};
+            StateName = case AuthorizeStatus =:= 1 of
+                            true  -> ?STATE_ACTIVATED;
+                            false -> ?STATE_DENIED
+                        end,
+            {ok, StateName, #state{host_id = HostId, uuid = UUID, aes = Aes, has_session = false}};
         undefined ->
             lager:warning("[iot_host] host uuid: ~p, loaded from mysql failed", [UUID]),
             ignore
     end.
 
 %% @private
-%% @doc Handling call messages
--spec(handle_call(Request :: term(), From :: {pid(), Tag :: term()},
-    State :: #state{}) ->
-    {reply, Reply :: term(), NewState :: #state{}} |
-    {reply, Reply :: term(), NewState :: #state{}, timeout() | hibernate} |
-    {noreply, NewState :: #state{}} |
-    {noreply, NewState :: #state{}, timeout() | hibernate} |
-    {stop, Reason :: term(), Reply :: term(), NewState :: #state{}} |
-    {stop, Reason :: term(), NewState :: #state{}}).
-handle_call(get_metric, _From, State = #state{metrics = Metrics}) ->
-    {reply, {ok, Metrics}, State};
+%% @doc This function is called by a gen_statem when it needs to find out
+%% the callback mode of the callback module.
+callback_mode() ->
+    handle_event_function.
 
-handle_call(get_aes, _From, State = #state{aes = Aes}) ->
-    {reply,  {ok, Aes}, State};
+%% @private
+%% @doc If callback_mode is handle_event_function, then whenever a
+%% gen_statem receives an event from call/2, cast/2, or as a normal
+%% process message, this function is called.
+
+handle_event({call, From}, get_metric, _, State = #state{metrics = Metrics}) ->
+    {keep_state, State, [{reply, From, {ok, Metrics}}]};
+
+handle_event({call, From}, get_aes, _, State = #state{aes = Aes}) ->
+    {keep_state, State, [{reply, From, {ok, Aes}}]};
 
 %% 获取主机的状态
-handle_call(get_status, _From, State = #state{host_id = HostId, last_status = LastStatus, channel_pid = ChannelPid, heartbeat_counter = HeartbeatCounter, metrics = Metrics, has_session = HasSession}) ->
+handle_event({call, From}, get_status, _, State = #state{host_id = HostId, channel_pid = ChannelPid, heartbeat_counter = HeartbeatCounter, metrics = Metrics, has_session = HasSession}) ->
     %% 启动主机相关的devices
     {ok, Devices} = device_bo:get_host_devices(HostId),
     DeviceInfos = lists:map(fun(DeviceUUID) ->
         DevicePid = iot_device:get_pid(DeviceUUID),
         case iot_device:is_activated(DevicePid) of
-            true ->
-                {DeviceUUID, <<"online">>};
-            false ->
-                {DeviceUUID, <<"offline">>}
+            true  -> {DeviceUUID, <<"activated">>};
+            false -> {DeviceUUID, <<"denied">>}
         end
                             end, Devices),
 
     HasChannel = (ChannelPid /= undefined),
     Reply = #{
-        <<"last_status">> => LastStatus,
         <<"has_channel">> => HasChannel,
         <<"has_session">> => HasSession,
         <<"heartbeat_counter">> => HeartbeatCounter,
         <<"metrics">> => Metrics,
         <<"device_infos">> => DeviceInfos
     },
-    {reply, {ok, Reply}, State};
+    {keep_state, State, [{reply, From, {ok, Reply}}]};
 
 %% 发送普通格式的消息, 激活的时候，会话时创建不成功的; 发送aes类型的命令的时候，必须要求session是存在的
-handle_call({publish_message, ReceiverPid, CommandType, {aes, Command0}}, _From, State = #state{uuid = UUID, aes = AES, channel_pid = ChannelPid, has_session = true}) ->
+handle_event({call, From}, {publish_message, ReceiverPid, CommandType, {aes, Command0}}, ?STATE_ACTIVATED,
+    State = #state{uuid = UUID, aes = AES, channel_pid = ChannelPid, has_session = true}) ->
+
     lager:debug("[iot_host] host: ~p, will publish aes message: ~p", [UUID, Command0]),
     Command = iot_cipher_aes:encrypt(AES, Command0),
     %% 通过websocket发送请求
     Ref = ws_channel:publish(ChannelPid, ReceiverPid, <<CommandType:8, Command/binary>>),
 
-    {reply, {ok, Ref}, State};
+    {keep_state, State, [{reply, From, {ok, Ref}}]};
 
 %% 只要channel存在，就负责将消息推送到边缘端主机
-handle_call({publish_message, ReceiverPid, CommandType, Command}, _From, State = #state{uuid = UUID, channel_pid = ChannelPid}) when is_binary(Command), is_pid(ChannelPid) ->
+handle_event({call, From}, {publish_message, ReceiverPid, CommandType, Command}, _,
+    State = #state{uuid = UUID, channel_pid = ChannelPid}) when is_binary(Command), is_pid(ChannelPid) ->
+
     %% 通过websocket发送请求
     lager:debug("[iot_host] host: ~p, will publish message: ~p", [UUID, Command]),
     Ref = ws_channel:publish(ChannelPid, ReceiverPid, <<CommandType:8, Command/binary>>),
 
-    {reply, {ok, Ref}, State};
+    {keep_state, State, [{reply, From, {ok, Ref}}]};
 
-handle_call({publish_message, _, _, _}, _From, State = #state{uuid = UUID}) ->
+handle_event({call, From}, {publish_message, _, _, _}, _, State = #state{uuid = UUID}) ->
     lager:debug("[iot_host] uuid: ~p, publish_message invalid state: ~p", [UUID, state_map(State)]),
-    {reply, {error, <<"主机状态错误，发送命令失败"/utf8>>}, State};
+    {keep_state, State, [{reply, From, {error, <<"主机离线，发送命令失败"/utf8>>}}]};
 
 %% 激活主机
-handle_call({activate, true}, _From, State = #state{uuid = UUID, aes = Aes, channel_pid = ChannelPid}) when is_pid(ChannelPid) ->
+handle_event({call, From}, {activate, true}, _, State = #state{uuid = UUID, aes = Aes, channel_pid = ChannelPid}) when is_pid(ChannelPid) ->
     BinReply = jiffy:encode(#{<<"auth">> => true, <<"aes">> => Aes}, [force_utf8]),
     ws_channel:send(ChannelPid, <<8:8, BinReply/binary>>),
     lager:debug("[iot_host] uuid: ~p, activate: true, will send message: ~p", [UUID, BinReply]),
-    {reply, ok, State};
-handle_call({activate, true}, _From, State = #state{uuid = UUID, channel_pid = undefined}) ->
+    {next_state, ?STATE_ACTIVATED, State, [{reply, From, ok}]};
+handle_event({call, From}, {activate, true}, _, State = #state{uuid = UUID, channel_pid = undefined}) ->
     lager:debug("[iot_host] uuid: ~p, activate: true, no channel", [UUID]),
-    {reply, ok, State};
+    {next_state, ?STATE_ACTIVATED, State, [{reply, From, ok}]};
 
 %% 关闭授权
-handle_call({activate, false}, _From, State = #state{uuid = UUID, host_id = HostId, channel_pid = ChannelPid}) ->
-    case is_pid(ChannelPid) of
-        true ->
-            BinReply = jiffy:encode(#{<<"auth">> => false}, [force_utf8]),
-            ws_channel:send(ChannelPid, <<8:8, BinReply/binary>>),
-            ws_channel:stop(ChannelPid, closed),
-            lager:debug("[iot_host] uuid: ~p, activate: false, will send message: ~p", [UUID, BinReply]);
-        false ->
-            lager:debug("[iot_host] uuid: ~p, activate: false, no channel", [UUID])
-    end,
+handle_event({call, From}, {activate, false}, _, State = #state{uuid = UUID, channel_pid = ChannelPid}) when is_pid(ChannelPid) ->
+    BinReply = jiffy:encode(#{<<"auth">> => false}, [force_utf8]),
+    ws_channel:send(ChannelPid, <<8:8, BinReply/binary>>),
+    ws_channel:stop(ChannelPid, closed),
+    lager:debug("[iot_host] uuid: ~p, activate: false, will send message: ~p", [UUID, BinReply]),
+    {next_state, ?STATE_DENIED, State#state{channel_pid = undefined, has_session = false}, [{reply, From, ok}]};
 
-    {ok, _} = host_bo:change_status(UUID, ?HOST_OFFLINE),
-    report_event(UUID, ?HOST_OFFLINE),
-    change_devices_status(HostId, ?DEVICE_UNKNOWN),
-
-    {reply, ok, State#state{last_status = ?HOST_OFFLINE, channel_pid = undefined, has_session = false}};
+handle_event({call, From}, {activate, false}, _, State = #state{uuid = UUID, channel_pid = undefined}) ->
+    lager:debug("[iot_host] uuid: ~p, activate: false, no channel", [UUID]),
+    {next_state, ?STATE_DENIED, State#state{has_session = false}, [{reply, From, ok}]};
 
 %% 绑定channel
-handle_call({attach_channel, ChannelPid}, _From, State = #state{uuid = UUID, channel_pid = OldChannelPid}) ->
+handle_event({call, From}, {attach_channel, ChannelPid}, _, State = #state{uuid = UUID, channel_pid = undefined}) ->
     lager:debug("[iot_host] attach_channel host_id uuid: ~p, channel: ~p", [UUID, ChannelPid]),
-    case OldChannelPid =:= undefined of
-        true ->
-            erlang:monitor(process, ChannelPid),
-            {reply, ok, State#state{channel_pid = ChannelPid}};
-        false ->
-            lager:debug("[iot_host] attach_channel host_id uuid: ~p, old channel exists: ~p", [UUID, OldChannelPid]),
-            {reply, {error, <<"channel existed">>}, State#state{channel_pid = ChannelPid}}
-    end;
+    erlang:monitor(process, ChannelPid),
+    {keep_state, State#state{channel_pid = ChannelPid}, [{reply, From, ok}]};
+
+handle_event({call, From}, {attach_channel, _}, _, State = #state{uuid = UUID, channel_pid = OldChannelPid}) ->
+    lager:notice("[iot_host] attach_channel host_id uuid: ~p, old channel exists: ~p", [UUID, OldChannelPid]),
+    {keep_state, State, [{reply, From, {error, <<"channel existed">>}}]};
 
 %% 授权通过后，才能将主机的状态设置为在线状态
-handle_call({create_session, PubKey}, _From, State = #state{uuid = UUID, aes = Aes}) ->
-    {ok, #{<<"authorize_status">> := AuthorizeStatus}} = host_bo:get_host_by_uuid(UUID),
-    case AuthorizeStatus =:= 1 of
-        true ->
-            Reply = #{<<"a">> => true, <<"aes">> => Aes},
-            EncReply = iot_cipher_rsa:encode(Reply, PubKey),
-            {ok, AffectedRow} = host_bo:change_status(UUID, ?HOST_ONLINE),
-            report_event(UUID, ?HOST_ONLINE),
+handle_event({call, From}, {create_session, PubKey}, ?STATE_ACTIVATED, State = #state{uuid = UUID, aes = Aes}) ->
+    Reply = #{<<"a">> => true, <<"aes">> => Aes},
+    EncReply = iot_cipher_rsa:encode(Reply, PubKey),
+    {ok, AffectedRow} = host_bo:change_status(UUID, ?HOST_ONLINE),
+    report_event(UUID, ?HOST_ONLINE),
+    lager:debug("[iot_host] host_id(session) uuid: ~p, create_session, will change status, affected_row: ~p", [UUID, AffectedRow]),
+    {keep_state, State#state{has_session = true}, [{reply, From, {ok, <<10:8, EncReply/binary>>}}]};
 
-            lager:debug("[iot_host] host_id(session) uuid: ~p, create_session, will change status, affected_row: ~p", [UUID, AffectedRow]),
-
-            {reply, {ok, <<10:8, EncReply/binary>>}, State#state{last_status = ?HOST_ONLINE, has_session = true}};
-        false ->
-            lager:debug("[iot_host] host_id(denied) uuid: ~p, create_session, will not change host status", [UUID]),
-            Reply = #{<<"a">> => false, <<"aes">> => <<"">>},
-            EncReply = iot_cipher_rsa:encode(Reply, PubKey),
-
-            {reply, {ok, <<10:8, EncReply/binary>>}, State#state{has_session = false}}
-    end;
+handle_event({call, From}, {create_session, PubKey}, ?STATE_DENIED, State = #state{uuid = UUID}) ->
+    lager:debug("[iot_host] host_id(denied) uuid: ~p, create_session, will not change host status", [UUID]),
+    Reply = #{<<"a">> => false, <<"aes">> => <<"">>},
+    EncReply = iot_cipher_rsa:encode(Reply, PubKey),
+    {keep_state, State#state{has_session = false}, [{reply, From, {ok, <<10:8, EncReply/binary>>}}]};
 
 %% 重新加载设备信息
-handle_call({reload_device, DeviceUUID}, _From, State) ->
+handle_event({call, From}, {reload_device, DeviceUUID}, _, State) ->
     case iot_device_sup:ensured_device_started(DeviceUUID) of
         {ok, DevicePid} ->
             iot_device:reload(DevicePid),
-            {reply, ok, State};
+            {keep_state, State, [{reply, From, ok}]};
         {error, Reason} ->
-            {reply, {error, Reason}, State}
+            {keep_state, State, [{reply, From, {error, Reason}}]}
     end;
 
 %% 删除设备
-handle_call({delete_device, DeviceUUID}, _From, State) ->
+handle_event({call, From}, {delete_device, DeviceUUID}, _, State) ->
     case iot_device:get_pid(DeviceUUID) of
         undefined ->
             ok;
         DevicePid when is_pid(DevicePid) ->
             iot_device_sup:delete_device(DeviceUUID)
     end,
-    {reply, ok, State};
+    {keep_state, State, [{reply, From, ok}]};
 
 %% 激活设备
-handle_call({activate_device, DeviceUUID, Auth}, _From, State) ->
+handle_event({call, From}, {activate_device, DeviceUUID, Auth}, _, State) ->
     case iot_device_sup:ensured_device_started(DeviceUUID) of
         {ok, DevicePid} ->
             iot_device:auth(DevicePid, Auth),
 
-            {reply, ok, State};
+            {keep_state, State, [{reply, From, ok}]};
         {error, Reason} ->
-            {reply, {error, Reason}, State}
-    end.
+            {keep_state, State, [{reply, From, {error, Reason}}]}
+    end;
 
--spec handle_cast(Request :: term(), State :: term()) ->
-    {noreply, NewState :: term()} |
-    {noreply, NewState :: term(), timeout() | hibernate | {continue, term()}} |
-    {stop, Reason :: term(), NewState :: term()}.
 %% 需要将消息转换成json格式然后再处理, 需要在host进程里面处理, 数据带有props，服务端暂时未用到
-handle_cast({handle, {data, Data}}, State = #state{aes = AES, has_session = true}) ->
+handle_event(cast, {handle, {data, Data}}, ?STATE_ACTIVATED, State = #state{aes = AES, has_session = true}) ->
     PlainData = iot_cipher_aes:decrypt(AES, Data),
     case catch jiffy:decode(PlainData, [return_maps]) of
         Info when is_map(Info) ->
             handle_data(Info, State);
         Other ->
-            lager:debug("[iot_host] the data is invalid json: ~p", [Other])
+            lager:notice("[iot_host] the data is invalid json: ~p", [Other])
     end,
-    {noreply, State};
+    {keep_state, State};
 
-%% 其他情况丢弃数据
-handle_cast({handle, {data, _}}, State = #state{has_session = false}) ->
-    {noreply, State};
-
-%% 任意状态下都可以ping
-handle_cast({handle, {ping, CipherMetric}}, State = #state{uuid = UUID, aes = AES}) ->
+%% ping的数据是通过aes加密后的，因此需要在有会话的情况下才行
+handle_event(cast, {handle, {ping, CipherMetric}}, ?STATE_ACTIVATED, State = #state{uuid = UUID, aes = AES, has_session = true}) ->
     MetricsInfo = iot_cipher_aes:decrypt(AES, CipherMetric),
     case catch jiffy:decode(MetricsInfo, [return_maps]) of
         Metrics when is_map(Metrics) ->
             lager:debug("[iot_host] host_id uuid: ~p, get ping: ~p", [UUID, Metrics]),
-            {noreply, State#state{metrics = Metrics}};
+            {keep_state, State#state{metrics = Metrics}};
         Other ->
             lager:warning("[iot_host] host_id: ~p, ping is invalid json: ~p", [UUID, Other]),
-            {noreply, State}
+            {keep_state, State}
     end;
 
-handle_cast({handle, {inform, Info0}}, State = #state{uuid = UUID, host_id = HostId, aes = AES, has_session = true}) ->
+handle_event(cast, {handle, {inform, Info0}}, ?STATE_ACTIVATED, State = #state{uuid = UUID, host_id = HostId, aes = AES, has_session = true}) ->
     Info = iot_cipher_aes:decrypt(AES, Info0),
     case catch jiffy:decode(Info, [return_maps]) of
         #{<<"at">> := At, <<"services">> := ServiceInforms} ->
@@ -377,9 +358,9 @@ handle_cast({handle, {inform, Info0}}, State = #state{uuid = UUID, host_id = Hos
         Error ->
             lager:warning("[iot_host] inform get error: ~p", [Error])
     end,
-    {noreply, State};
+    {keep_state, State};
 
-handle_cast({handle, {feedback_step, Info0}}, State = #state{aes = AES, has_session = true}) ->
+handle_event(cast, {handle, {feedback_step, Info0}}, ?STATE_ACTIVATED, State = #state{aes = AES, has_session = true}) ->
     Info = iot_cipher_aes:decrypt(AES, Info0),
     case catch jiffy:decode(Info, [return_maps]) of
         Data = #{<<"task_id">> := TaskId, <<"code">> := Code} ->
@@ -392,9 +373,9 @@ handle_cast({handle, {feedback_step, Info0}}, State = #state{aes = AES, has_sess
         Other ->
             lager:warning("[iot_host] feedback_step error: ~p", [Other])
     end,
-    {noreply, State};
+    {keep_state, State};
 
-handle_cast({handle, {feedback_result, Info0}}, State = #state{aes = AES, has_session = true}) ->
+handle_event(cast, {handle, {feedback_result, Info0}}, ?STATE_ACTIVATED, State = #state{aes = AES, has_session = true}) ->
     Info = iot_cipher_aes:decrypt(AES, Info0),
     case catch jiffy:decode(Info, [return_maps]) of
         #{<<"task_id">> := TaskId, <<"time">> := Time, <<"code">> := Code, <<"reason">> := Reason, <<"error">> := Error, <<"type">> := Type} ->
@@ -409,9 +390,9 @@ handle_cast({handle, {feedback_result, Info0}}, State = #state{aes = AES, has_se
         Other ->
             lager:warning("[iot_host] feedback_result error: ~p", [Other])
     end,
-    {noreply, State};
+    {keep_state, State};
 
-handle_cast({handle, {event, Event0}}, State = #state{uuid = UUID, aes = AES, has_session = true}) ->
+handle_event(cast, {handle, {event, Event0}}, ?STATE_ACTIVATED, State = #state{uuid = UUID, aes = AES, has_session = true}) ->
     EventText = iot_cipher_aes:decrypt(AES, Event0),
     lager:debug("[iot_host] uuid: ~p, get event: ~p", [UUID, EventText]),
     case catch jiffy:decode(EventText, [return_maps]) of
@@ -423,75 +404,68 @@ handle_cast({handle, {event, Event0}}, State = #state{uuid = UUID, aes = AES, ha
         Other ->
             lager:warning("[iot_host] host: ~p, event error: ~p", [UUID, Other])
     end,
-    {noreply, State};
+    {keep_state, State};
 
 %% 心跳机制
-handle_cast(heartbeat, State = #state{heartbeat_counter = HeartbeatCounter}) ->
-    {noreply, State#state{heartbeat_counter = HeartbeatCounter + 1}}.
+handle_event(cast, heartbeat, _, State = #state{heartbeat_counter = HeartbeatCounter}) ->
+    {keep_state, State#state{heartbeat_counter = HeartbeatCounter + 1}};
 
--spec handle_info(Info :: timeout | term(), State :: term()) ->
-    {noreply, NewState :: term()} |
-    {noreply, NewState :: term(), timeout() | hibernate | {continue, term()}} |
-    {stop, Reason :: term(), NewState :: term()}.
-%% 没有收到心跳包，主机下线，设备状态变为: "未知"
-handle_info({timeout, _, heartbeat_ticker}, State = #state{uuid = UUID, host_id = HostId, heartbeat_counter = 0, has_session = false}) ->
+%% 没有收到心跳包，主机下线, 设备状态不变
+handle_event(info, {timeout, _, heartbeat_ticker}, _, State = #state{uuid = UUID, heartbeat_counter = 0, channel_pid = ChannelPid}) ->
     lager:warning("[iot_host] uuid: ~p, heartbeat lost, devices will unknown", [UUID]),
-    change_devices_status(HostId, ?DEVICE_UNKNOWN),
-    {ok, _} = host_bo:change_status(UUID, ?HOST_OFFLINE),
-    report_event(UUID, ?HOST_OFFLINE),
+    {ok, #{<<"status">> := Status}} = host_bo:get_host_by_uuid(UUID),
+    case Status of
+        ?HOST_NOT_JOINED ->
+            lager:debug("[iot_host] host: ~p, host_maybe_offline, host not joined, can not change to offline", [UUID]);
+        ?HOST_OFFLINE ->
+            lager:debug("[iot_host] host: ~p, host_maybe_offline, host now is offline, do nothing", [UUID]);
+        ?HOST_ONLINE ->
+            {ok, _} = host_bo:change_status(UUID, ?HOST_OFFLINE),
+            report_event(UUID, ?HOST_OFFLINE)
+    end,
 
+    %% 关闭channel，主机需要重新连接，才能保存状态的一致
+    is_pid(ChannelPid) andalso ws_channel:stop(ChannelPid, closed),
     erlang:start_timer(?HEARTBEAT_INTERVAL, self(), heartbeat_ticker),
-    {noreply, State#state{last_status = ?HOST_OFFLINE, heartbeat_counter = 0}};
+
+    {keep_state, State#state{channel_pid = undefined, has_session = false, heartbeat_counter = 0}};
+
 %% 其他情况下需要重置系统计数器
-handle_info({timeout, _, heartbeat_ticker}, State = #state{}) ->
+handle_event(info, {timeout, _, heartbeat_ticker}, _, State = #state{}) ->
     erlang:start_timer(?HEARTBEAT_INTERVAL, self(), heartbeat_ticker),
-    {noreply, State#state{heartbeat_counter = 0}};
+    {keep_state, State#state{heartbeat_counter = 0}};
 
 %% 当websocket断开的时候，主机的状态不一定改变；主机的状态改变通过心跳机制，会话状态需要改变
-handle_info({'DOWN', _Ref, process, ChannelPid, Reason}, State = #state{uuid = UUID, channel_pid = ChannelPid, has_session = HasSession}) ->
+handle_event(info, {'DOWN', _Ref, process, ChannelPid, Reason}, _, State = #state{uuid = UUID, channel_pid = ChannelPid, has_session = HasSession}) ->
     lager:warning("[iot_host] uuid: ~p, channel: ~p, down with reason: ~p, has_session: ~p, state: ~p", [UUID, ChannelPid, Reason, HasSession, State]),
-    {noreply, State#state{channel_pid = undefined, has_session = false}};
+    {keep_state, State#state{channel_pid = undefined, has_session = false}};
 
-handle_info({'DOWN', _Ref, process, Pid, Reason}, State = #state{uuid = UUID}) ->
+handle_event(info, {'DOWN', _Ref, process, Pid, Reason}, _, State = #state{uuid = UUID}) ->
     lager:debug("[iot_host] uuid: ~p, process_pid: ~p, down with reason: ~p, state: ~p", [UUID, Pid, Reason, State]),
-    {noreply, State};
+    {keep_state, State};
 
-handle_info(Info, State = #state{has_session = HasSession}) ->
-    lager:warning("[iot_host] unknown info: ~p, state: ~p", [Info, HasSession]),
-
-    {noreply, State}.
+handle_event(Event, Info, StateName, State = #state{uuid = UUID}) ->
+    lager:warning("[iot_host] host: ~p, event: ~p, unknown message: ~p, state_name: ~p, state: ~p", [UUID, Event, Info, StateName, state_map(State)]),
+    {keep_state, State}.
 
 %% @private
 %% @doc This function is called by a gen_statem when it is about to
 %% terminate. It should be the opposite of Module:init/1 and do any
 %% necessary cleaning up. When it returns, the gen_statem terminates with
 %% Reason. The return value is ignored.
-terminate(Reason, #state{host_id = HostId, uuid = UUID, has_session = HasSession}) ->
-    lager:debug("[iot_host] host: ~p, terminate with reason: ~p, has_session: ~p, status: offline", [UUID, Reason, HasSession]),
-    host_bo:change_status(UUID, ?HOST_OFFLINE),
-    report_event(UUID, ?HOST_OFFLINE),
-
-    change_devices_status(HostId, ?DEVICE_UNKNOWN),
+terminate(Reason, _StateName, _State = #state{uuid = UUID, has_session = HasSession}) ->
+    lager:debug("[iot_host] host: ~p, terminate with reason: ~p, has_session: ~p", [UUID, Reason, HasSession]),
     ok.
 
 %% @private
 %% @doc Convert process state when code is changed
-code_change(_OldVsn, State = #state{}, _Extra) ->
-    {ok, State}.
+code_change(_OldVsn, StateName, State = #state{}, _Extra) ->
+    {ok, StateName, State}.
 
 %%%===================================================================
 %%% Internal functions
 %%%===================================================================
 
-%% 修改设备的状态
-change_devices_status(HostId, NewStatus) when is_integer(HostId), is_integer(NewStatus) ->
-    {ok, Devices} = device_bo:get_host_devices(HostId),
-    lager:debug("[iot_host] host_id: ~p, devices new status: ~p, devices: ~p", [HostId, NewStatus, Devices]),
-    lists:foreach(fun(DeviceUUID) ->
-        Pid = iot_device:get_pid(DeviceUUID),
-        iot_device:change_status(Pid, NewStatus)
-                  end, Devices).
-
 %% 处理相关数据
 handle_data(#{<<"device_uuid">> := DeviceUUID, <<"service_name">> := ServiceName, <<"at">> := Timestamp, <<"fields">> := FieldsList, <<"tags">> := Tags}, #state{uuid = UUID})
     when is_binary(DeviceUUID), DeviceUUID /= <<>> ->
@@ -527,11 +501,17 @@ handle_data(#{<<"service_name">> := ServiceName, <<"at">> := Timestamp, <<"field
 
 -spec report_event(UUID :: binary(), NewStatus :: integer()) -> no_return().
 report_event(UUID, NewStatus) when is_binary(UUID), is_integer(NewStatus) ->
+    TextMap = #{
+        0 => <<"离线"/utf8>>,
+        1 => <<"在线"/utf8>>
+    },
+
     %% 设备的状态信息上报给中电
     Timestamp = iot_util:timestamp_of_seconds(),
     FieldsList = [#{
         <<"key">> => <<"host_status">>,
         <<"value">> => NewStatus,
+        <<"value_text">> => maps:get(NewStatus, TextMap),
         <<"unit">> => 0,
         <<"type">> => <<"DI">>,
         <<"name">> => <<"主机状态"/utf8>>,
diff --git a/apps/iot/src/iot_host_sup.erl b/apps/iot/src/iot_host_sup.erl
index c3e5b4a..76c28bc 100644
--- a/apps/iot/src/iot_host_sup.erl
+++ b/apps/iot/src/iot_host_sup.erl
@@ -37,7 +37,8 @@ ensured_host_started(UUID) when is_binary(UUID) ->
 
 delete_host(UUID) when is_binary(UUID) ->
     Id = iot_host:get_name(UUID),
-    supervisor:terminate_child(?MODULE, Id).
+    ok = supervisor:terminate_child(?MODULE, Id),
+    supervisor:delete_child(?MODULE, Id).
 
 child_spec(UUID) ->
     Id = iot_host:get_name(UUID),
diff --git a/apps/iot/src/iot_sup.erl b/apps/iot/src/iot_sup.erl
index a61c3b9..2e16bf4 100644
--- a/apps/iot/src/iot_sup.erl
+++ b/apps/iot/src/iot_sup.erl
@@ -39,6 +39,15 @@ init([]) ->
             modules => ['iot_logger']
         },
 
+        #{
+            id => 'iot_database_buffer',
+            start => {'iot_database_buffer', start_link, []},
+            restart => permanent,
+            shutdown => 2000,
+            type => supervisor,
+            modules => ['iot_database_buffer']
+        },
+
         #{
             id => 'iot_device_sup',
             start => {'iot_device_sup', start_link, []},
diff --git a/config/sys-dev.config b/config/sys-dev.config
index c38304f..6e49305 100644
--- a/config/sys-dev.config
+++ b/config/sys-dev.config
@@ -65,7 +65,8 @@
         [{size, 10}, {max_overflow, 20}, {worker_module, eredis}],
         [
           {host, "127.0.0.1"},
-          {port, 26379}
+          {port, 26379},
+          {database, 1}
         ]
       },
 
diff --git a/config/sys-prod.config b/config/sys-prod.config
index 03124d9..8d015b2 100644
--- a/config/sys-prod.config
+++ b/config/sys-prod.config
@@ -54,7 +54,8 @@
         [{size, 10}, {max_overflow, 20}, {worker_module, eredis}],
         [
           {host, "172.19.0.7"},
-          {port, 6379}
+          {port, 6379},
+          {database, 1}
         ]
       },