diff --git a/etc/emqx.conf b/etc/emqx.conf
index c5943ce80..9ce950aae 100644
--- a/etc/emqx.conf
+++ b/etc/emqx.conf
@@ -354,8 +354,8 @@ log.to = both
 ## Note: Only the messages with severity level higher than or equal to
 ##       this level will be logged.
 ##
-## Default: error
-log.level = error
+## Default: warning
+log.level = warning
 
 ## The dir for log files.
 ##
diff --git a/priv/emqx.schema b/priv/emqx.schema
index 497b8f47c..1366665ca 100644
--- a/priv/emqx.schema
+++ b/priv/emqx.schema
@@ -396,12 +396,12 @@ end}.
 ]}.
 
 {mapping, "log.level", "kernel.logger", [
-  {default, error},
+  {default, warning},
   {datatype, {enum, [debug, info, notice, warning, error, critical, alert, emergency, all]}}
 ]}.
 
 {mapping, "log.primary_log_level", "kernel.logger_level", [
-   {default, error},
+   {default, warning},
    {datatype, {enum, [debug, info, notice, warning, error, critical, alert, emergency, all]}}
 ]}.
 
diff --git a/src/emqx_alarm_handler.erl b/src/emqx_alarm_handler.erl
index a7654e32c..77cc09c60 100644
--- a/src/emqx_alarm_handler.erl
+++ b/src/emqx_alarm_handler.erl
@@ -95,7 +95,7 @@ init(_) ->
 handle_event({set_alarm, {AlarmId, AlarmDesc = #alarm{timestamp = undefined}}}, State) ->
     handle_event({set_alarm, {AlarmId, AlarmDesc#alarm{timestamp = os:timestamp()}}}, State);
 handle_event({set_alarm, Alarm = {AlarmId, AlarmDesc}}, State) ->
-    ?LOG(warning, "~p set", [Alarm]),
+    ?LOG(warning, "New Alarm: ~p, Alarm Info: ~p", [AlarmId, AlarmDesc]),
     case encode_alarm(Alarm) of
         {ok, Json} ->
             emqx_broker:safe_publish(alarm_msg(topic(alert), Json));
@@ -105,7 +105,7 @@ handle_event({set_alarm, Alarm = {AlarmId, AlarmDesc}}, State) ->
     set_alarm_(AlarmId, AlarmDesc),
     {ok, State};
 handle_event({clear_alarm, AlarmId}, State) ->
-    ?LOG(notice, "~p clear", [AlarmId]),
+    ?LOG(warning, "Clear Alarm: ~p", [AlarmId]),
     case encode_alarm({AlarmId, undefined}) of
         {ok, Json} ->
             emqx_broker:safe_publish(alarm_msg(topic(clear), Json));
@@ -138,9 +138,9 @@ init_tables(ExistingAlarms) ->
                       set_alarm_history(Id)
                   end, ExistingAlarms).
 
-encode_alarm({AlarmId, #alarm{severity  = Severity, 
+encode_alarm({AlarmId, #alarm{severity  = Severity,
                               title     = Title,
-                              summary   = Summary, 
+                              summary   = Summary,
                               timestamp = Ts}}) ->
     emqx_json:safe_encode([{id, maybe_to_binary(AlarmId)},
                            {desc, [{severity, Severity},
diff --git a/src/emqx_session_sup.erl b/src/emqx_session_sup.erl
index b271bd85d..8c176edb2 100644
--- a/src/emqx_session_sup.erl
+++ b/src/emqx_session_sup.erl
@@ -119,7 +119,7 @@ handle_info({'EXIT', Pid, _Reason}, State = #state{sessions = SessMap, clean_dow
     {noreply, State#state{sessions = SessMap1}};
 
 handle_info(Info, State) ->
-    ?LOG(notice, "Unexpected info: ~p", [Info]),
+    ?LOG(error, "Unexpected info: ~p", [Info]),
     {noreply, State}.
 
 terminate(_Reason, State) ->
diff --git a/test/emqx_protocol_SUITE.erl b/test/emqx_protocol_SUITE.erl
index ec707e30d..17c55f517 100644
--- a/test/emqx_protocol_SUITE.erl
+++ b/test/emqx_protocol_SUITE.erl
@@ -245,7 +245,7 @@ connect_v5(_) ->
                                                       #{version => ?MQTT_PROTO_V5}
                                                   )),
 
-                            {ok, Data3} = gen_tcp:recv(Sock, 0),
+                            {ok, Data3} = gen_tcp:recv(Sock, 6),
 
                             {ok, ?PUBACK_PACKET(1, 0), <<>>, _} = raw_recv_parse(Data3, ?MQTT_PROTO_V5),
 
diff --git a/test/emqx_tracer_SUITE.erl b/test/emqx_tracer_SUITE.erl
index 0e04de963..8d516e94d 100644
--- a/test/emqx_tracer_SUITE.erl
+++ b/test/emqx_tracer_SUITE.erl
@@ -75,4 +75,4 @@ start_traces(_Config) ->
     ok = emqx_tracer:stop_trace({topic, <<"a/#">>}),
     emqx_client:disconnect(T),
 
-    emqx_logger:set_log_level(error).
+    emqx_logger:set_log_level(warning).