diff --git a/apps/roster/src/roster_log_utils.erl b/apps/roster/src/roster_log_utils.erl
new file mode 100644
index 0000000000000000000000000000000000000000..f63c5cddc0ac9707b8737ad69fd2ba2c7127a6fa
--- /dev/null
+++ b/apps/roster/src/roster_log_utils.erl
@@ -0,0 +1,21 @@
+%%%-------------------------------------------------------------------
+%%% @doc Utility functions to interact with logger.
+%%%
+%%% @end
+%%%-------------------------------------------------------------------
+
+-module(roster_log_utils).
+
+-export([ turn_on_debug_log/0
+        , turn_off_debug_log/0
+        , set_system_log_level/1
+        ]).
+
+turn_on_debug_log() ->
+    logger:update_handler_config(debug_handler, #{filter_default => log}).
+
+turn_off_debug_log() ->
+    logger:update_handler_config(debug_handler, #{filter_default => stop}).
+
+set_system_log_level(Level) ->
+    logger:set_primary_config(level, Level).
diff --git a/rebar.config b/rebar.config
index c2615b3fbbde4496b5cbac9643076ff54c289b4b..746c0e9436b5ca18f8d7c8127458c36755160aeb 100644
--- a/rebar.config
+++ b/rebar.config
@@ -10,7 +10,7 @@
     {bert,                  {git, "git://github.com/NYNJA-MC/bert.git", {branch, master}}},
     {esockd,                {git, "https://github.com/voxoz/esockd", {branch, "master"}}},
     {bpe,                   {git, "git://github.com/synrc/bpe", {tag,"4.4"}}},
-    {emqttd,                {git, "git://github.com/NYNJA-MC/emqttd", {branch,"master"}}},
+    {emqttd,                {git, "git://github.com/NYNJA-MC/emqttd", {branch,"switch-from-lager-to-logger"}}},
     {n2o,                   {git, "git://github.com/NYNJA-MC/n2o", {branch,"v6.4-otp21"}}},
     {emqttc,                {git, "git://github.com/NYNJA-MC/emqttc", {branch,"master"}}},
     {rest,                  {git, "git://github.com/synrc/rest", {tag,"5.10"}}},
@@ -83,7 +83,7 @@
           certifi,ibrowse,asn1,xmerl,counters,ctx,
           wts,syntax_tools,qdate_localtime,
           libphonenumber_erlang,syn,cowlib,jiffy,idna,parse_trans,
-          goldrush, public_key,bpe,lager,ssl,ranch,
+          goldrush, public_key,bpe,{lager,load},ssl,ranch,
           ssl_verify_fun,locus,emqttd,hackney,roster,service,active,
           cowboy,emq_dashboard,emqttc,enenra,envy,uuid,erlydtl,forms,
           gen_smtp, jwt, mini_s3, nitro, opencensus,
diff --git a/rebar.lock b/rebar.lock
index d4cf166bb582e41e3cd60853110e651696f6267f..be33a79052f095ab3b45108409f64ed4c94d7076 100644
--- a/rebar.lock
+++ b/rebar.lock
@@ -43,7 +43,7 @@
   0},
  {<<"emqttd">>,
   {git,"git://github.com/NYNJA-MC/emqttd",
-       {ref,"364bf8d4979884fc5e9e765c0fa92d97b78a8fa9"}},
+       {ref,"82488e8cf78fddb025a0dcc6e3caa567e75918bf"}},
   0},
  {<<"enenra">>,
   {git,"https://github.com/nlfiedler/enenra",
diff --git a/sys.config b/sys.config
index 49650bba38943040d322b4cd962109f762fb2867..a50aeb27c92ce4a2d6559cc2484d00c6289f330c 100644
--- a/sys.config
+++ b/sys.config
@@ -33,6 +33,7 @@
                    , max_no_bytes => 10000000
                    , filesync_repeat_interval => 1000
                    },
+        filter_default => stop,
         formatter => {logger_formatter,
                       #{template => [time," [",level,"] ",pid," [", mfa, "] ", msg,"\n"]}}
        }}