diff --git a/src/emqttd_server.erl b/src/emqttd_server.erl
index 38e7be311..8552054c8 100644
--- a/src/emqttd_server.erl
+++ b/src/emqttd_server.erl
@@ -92,7 +92,7 @@ publish(Msg = #mqtt_message{from = From}) ->
         {ok, Msg1 = #mqtt_message{topic = Topic}} ->
             emqttd_pubsub:publish(Topic, Msg1);
         {stop, Msg1} ->
-            lager:warning("Stop publishing: ~s", [emqttd_message:format(Msg1)]),
+            lager:info("Stop publishing: ~s", [emqttd_message:format(Msg1)]),
             ignore
     end.
 
diff --git a/src/emqttd_stats.erl b/src/emqttd_stats.erl
index 4471a2814..bfd60ea15 100644
--- a/src/emqttd_stats.erl
+++ b/src/emqttd_stats.erl
@@ -143,7 +143,7 @@ setstat(Stat, Val) ->
     ets:update_element(?STATS_TAB, Stat, {2, Val}).
 
 %% @doc Set stats with max
--spec(setstats(Stat :: atom(), MaxStat :: atom(), Val :: pos_integer()) -> boolean()).
+-spec(setstats(Stat :: atom(), MaxStat :: atom(), Val :: pos_integer()) -> ok).
 setstats(Stat, MaxStat, Val) ->
     gen_server:cast(?MODULE, {setstats, Stat, MaxStat, Val}).
 
diff --git a/src/emqttd_vm.erl b/src/emqttd_vm.erl
index 368463d35..b23b884fa 100644
--- a/src/emqttd_vm.erl
+++ b/src/emqttd_vm.erl
@@ -156,9 +156,9 @@ microsecs() ->
     (Mega * 1000000 + Sec) * 1000000 + Micro.
 
 loads() ->
-    [{load1,  ftos(cpu_sup:avg1()/256)},
-     {load5,  ftos(cpu_sup:avg5()/256)},
-     {load15, ftos(cpu_sup:avg15()/256)}].
+    [{load1,  ftos(avg1()/256)},
+        {load5,  ftos(avg5()/256)},
+        {load15, ftos(avg15()/256)}].
 
 get_system_info() ->
     [{Key, format_system_info(Key, get_system_info(Key))} || Key <- ?SYSTEM_INFO].
@@ -427,3 +427,27 @@ mapping([{owner, V}|Entries], Acc) when is_pid(V) ->
 mapping([{Key, Value}|Entries], Acc) ->
     mapping(Entries, [{Key, Value}|Acc]).
 
+avg1() ->
+   case cpu_sup:avg1() of
+        SystemLoad when is_integer(SystemLoad) ->
+            SystemLoad;
+        {error, Reason} ->
+            lager:error("Get the average system load in the last minute fail for ~p~n", [Reason]),
+            0.00
+    end.
+avg5() ->
+    case cpu_sup:avg5() of
+        SystemLoad when is_integer(SystemLoad) ->
+            SystemLoad;
+        {error, Reason} ->
+            lager:error("Get the average system load in the last 5 minutes fail for ~p~n", [Reason]),
+            0.00
+    end.
+avg15() ->
+    case cpu_sup:avg15() of
+        SystemLoad when is_integer(SystemLoad) ->
+            SystemLoad;
+        {error, Reason} ->
+            lager:error("Get the average system load in the last 15 minutes fail for ~p~n", [Reason]),
+            0.00
+    end.