diff --git a/src/emqttd_broker.erl b/src/emqttd_broker.erl
index f68a4deff..5a26fd291 100644
--- a/src/emqttd_broker.erl
+++ b/src/emqttd_broker.erl
@@ -14,8 +14,6 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
-%% @doc emqttd broker
-%% @author Feng Lee <feng@emqtt.io>
 -module(emqttd_broker).
 
 -behaviour(gen_server).
@@ -27,9 +25,6 @@
 %% API Function Exports
 -export([start_link/0]).
 
-%% Running nodes
--export([running_nodes/0]).
-
 %% Event API
 -export([subscribe/1, notify/2]).
 
@@ -69,11 +64,6 @@
 start_link() ->
     gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
 
-%% @doc Get running nodes
--spec running_nodes() -> list(node()).
-running_nodes() ->
-    mnesia:system_info(running_db_nodes).
-
 %% @doc Subscribe broker event
 -spec subscribe(EventType :: any()) -> ok.
 subscribe(EventType) ->
@@ -82,8 +72,7 @@ subscribe(EventType) ->
 %% @doc Notify broker event
 -spec notify(EventType :: any(), Event :: any()) -> ok.
 notify(EventType, Event) ->
-     Key = {broker, EventType},
-     gproc:send({p, l, Key}, {self(), Key, Event}).
+     gproc:send({p, l, {broker, EventType}}, {notify, EventType, self(), Event}).
 
 %% @doc Get broker env
 env(Name) ->
@@ -101,8 +90,7 @@ sysdescr() ->
 
 %% @doc Get broker uptime
 -spec uptime() -> string().
-uptime() ->
-    gen_server:call(?SERVER, uptime).
+uptime() -> gen_server:call(?SERVER, uptime).
 
 %% @doc Get broker datetime
 -spec datetime() -> string().
@@ -166,7 +154,7 @@ stop_tick(TRef) ->
 %%--------------------------------------------------------------------
 
 init([]) ->
-    emqttd:seed_now(),
+    emqttd_time:seed(),
     ets:new(?BROKER_TAB, [set, public, named_table]),
     % Create $SYS Topics
     emqttd_pubsub:create(topic, <<"$SYS/brokers">>),
@@ -182,24 +170,24 @@ handle_call(uptime, _From, State) ->
 handle_call({hook, Hook, Name, MFArgs}, _From, State) ->
     Key = {hook, Hook}, Reply =
     case ets:lookup(?BROKER_TAB, Key) of
-        [{Key, Hooks}] -> 
+        [{Key, Hooks}] ->
             case lists:keyfind(Name, 1, Hooks) of
                 {Name, _MFArgs} ->
                     {error, existed};
                 false ->
-                    ets:insert(?BROKER_TAB, {Key, Hooks ++ [{Name, MFArgs}]})
+                    insert_hooks(Key, Hooks ++ [{Name, MFArgs}])
             end;
-        [] -> 
-            ets:insert(?BROKER_TAB, {Key, [{Name, MFArgs}]})
+        [] ->
+            insert_hooks(Key, [{Name, MFArgs}])
     end,
     {reply, Reply, State};
 
 handle_call({unhook, Hook, Name}, _From, State) ->
     Key = {hook, Hook}, Reply =
     case ets:lookup(?BROKER_TAB, Key) of
-        [{Key, Hooks}] -> 
-            ets:insert(?BROKER_TAB, {Key, lists:keydelete(Name, 1, Hooks)}); 
-        [] -> 
+        [{Key, Hooks}] ->
+            insert_hooks(Key, lists:keydelete(Name, 1, Hooks));
+        [] ->
             {error, not_found}
     end,
     {reply, Reply, State};
@@ -236,11 +224,15 @@ code_change(_OldVsn, State, _Extra) ->
 %% Internal functions
 %%--------------------------------------------------------------------
 
+insert_hooks(Key, Hooks) ->
+    ets:insert(?BROKER_TAB, {Key, Hooks}), ok.
+
 create_topic(Topic) ->
     emqttd_pubsub:create(topic, emqttd_topic:systop(Topic)).
 
 retain(brokers) ->
-    Payload = list_to_binary(string:join([atom_to_list(N) || N <- running_nodes()], ",")),
+    Payload = list_to_binary(string:join([atom_to_list(N) ||
+                    N <- emqttd_mnesia:running_nodes()], ",")),
     Msg = emqttd_message:make(broker, <<"$SYS/brokers">>, Payload),
     emqttd_pubsub:publish(emqttd_message:set_flag(sys, Msg)).