diff --git a/rebar.config b/rebar.config
index 7a2c67eb1..98ce306f0 100644
--- a/rebar.config
+++ b/rebar.config
@@ -3,7 +3,7 @@
 {deps,
     [{jsx, "2.10.0"},
      {gproc, "0.8.0"},
-     {cowboy, {git, "https://github.com/emqx/cowboy", {tag, "2.8.1"}}},
+     {cowboy, {git, "https://github.com/emqx/cowboy", {tag, "2.7.1"}}},
      {esockd, {git, "https://github.com/emqx/esockd", {tag, "5.6.0"}}},
      {ekka, {git, "https://github.com/emqx/ekka", {tag, "0.7.1"}}},
      {gen_rpc, {git, "https://github.com/emqx/gen_rpc", {tag, "2.4.1"}}},
diff --git a/src/emqx_connection.erl b/src/emqx_connection.erl
index 3461788d5..7fb8756a3 100644
--- a/src/emqx_connection.erl
+++ b/src/emqx_connection.erl
@@ -51,7 +51,7 @@
         ]).
 
 %% Internal callback
--export([wakeup_from_hib/3]).
+-export([wakeup_from_hib/2]).
 
 %% Export for CT
 -export([set_field/3]).
@@ -89,7 +89,9 @@
           %% Stats Timer
           stats_timer :: disabled | maybe(reference()),
           %% Idle Timer
-          idle_timer :: maybe(reference())
+          idle_timer :: maybe(reference()),
+          %% Idle Timeout
+          idle_timeout :: integer()
         }).
 
 -type(state() :: #state{}).
@@ -166,13 +168,13 @@ stop(Pid) ->
 init(Parent, Transport, RawSocket, Options) ->
     case Transport:wait(RawSocket) of
         {ok, Socket} ->
-            do_init(Parent, Transport, Socket, Options);
+            run_loop(Parent, init_state(Transport, Socket, Options));
         {error, Reason} ->
             ok = Transport:fast_close(RawSocket),
             exit_on_sock_error(Reason)
     end.
 
-do_init(Parent, Transport, Socket, Options) ->
+init_state(Transport, Socket, Options) ->
     {ok, Peername} = Transport:ensure_ok_or_exit(peername, [Socket]),
     {ok, Sockname} = Transport:ensure_ok_or_exit(sockname, [Socket]),
     Peercert = Transport:ensure_ok_or_exit(peercert, [Socket]),
@@ -194,25 +196,31 @@ do_init(Parent, Transport, Socket, Options) ->
     StatsTimer = emqx_zone:stats_timer(Zone),
     IdleTimeout = emqx_zone:idle_timeout(Zone),
     IdleTimer = start_timer(IdleTimeout, idle_timeout),
-    emqx_misc:tune_heap_size(emqx_zone:oom_policy(Zone)),
+    #state{transport    = Transport,
+           socket       = Socket,
+           peername     = Peername,
+           sockname     = Sockname,
+           sockstate    = idle,
+           active_n     = ActiveN,
+           limiter      = Limiter,
+           parse_state  = ParseState,
+           serialize    = Serialize,
+           channel      = Channel,
+           gc_state     = GcState,
+           stats_timer  = StatsTimer,
+           idle_timer   = IdleTimer,
+           idle_timeout = IdleTimeout
+          }.
+
+run_loop(Parent, State = #state{transport = Transport,
+                                socket    = Socket,
+                                peername  = Peername,
+                                channel   = Channel}) ->
     emqx_logger:set_metadata_peername(esockd:format(Peername)),
-    State = #state{transport   = Transport,
-                   socket      = Socket,
-                   peername    = Peername,
-                   sockname    = Sockname,
-                   sockstate   = idle,
-                   active_n    = ActiveN,
-                   limiter     = Limiter,
-                   parse_state = ParseState,
-                   serialize   = Serialize,
-                   channel     = Channel,
-                   gc_state    = GcState,
-                   stats_timer = StatsTimer,
-                   idle_timer  = IdleTimer
-                  },
+    emqx_misc:tune_heap_size(emqx_zone:oom_policy(
+                               emqx_channel:info(zone, Channel))),
     case activate_socket(State) of
-        {ok, NState} ->
-            hibernate(Parent, NState, #{idle_timeout => IdleTimeout});
+        {ok, NState} -> hibernate(Parent, NState);
         {error, Reason} ->
             ok = Transport:fast_close(Socket),
             exit_on_sock_error(Reason)
@@ -230,28 +238,24 @@ exit_on_sock_error(Reason) ->
 %%--------------------------------------------------------------------
 %% Recv Loop
 
-recvloop(Parent, State, Options = #{idle_timeout := IdleTimeout}) ->
+recvloop(Parent, State = #state{idle_timeout = IdleTimeout}) ->
     receive
         {system, From, Request} ->
-            sys:handle_system_msg(Request, From, Parent,
-                                  ?MODULE, [], {State, Options});
+            sys:handle_system_msg(Request, From, Parent, ?MODULE, [], State);
         {'EXIT', Parent, Reason} ->
             terminate(Reason, State);
         Msg ->
-            NState = ensure_stats_timer(IdleTimeout, State),
-            process_msg([Msg], Parent, NState, Options)
+            process_msg([Msg], Parent, ensure_stats_timer(IdleTimeout, State))
     after
         IdleTimeout ->
-            NState = cancel_stats_timer(State),
-            hibernate(Parent, NState, Options)
+            hibernate(Parent, cancel_stats_timer(State))
     end.
 
-hibernate(Parent, State, Options) ->
-    proc_lib:hibernate(?MODULE, wakeup_from_hib, [Parent, State, Options]).
+hibernate(Parent, State) ->
+    proc_lib:hibernate(?MODULE, wakeup_from_hib, [Parent, State]).
 
-wakeup_from_hib(Parent, State, Options) ->
-    %% Maybe do something later here.
-    recvloop(Parent, State, Options).
+%% Maybe do something here later.
+wakeup_from_hib(Parent, State) -> recvloop(Parent, State).
 
 %%--------------------------------------------------------------------
 %% Ensure/cancel stats timer
@@ -270,17 +274,16 @@ cancel_stats_timer(State) -> State.
 %%--------------------------------------------------------------------
 %% Process next Msg
 
-process_msg([], Parent, State, Options) ->
-    recvloop(Parent, State, Options);
+process_msg([], Parent, State) -> recvloop(Parent, State);
 
-process_msg([Msg|More], Parent, State, Options) ->
+process_msg([Msg|More], Parent, State) ->
     case catch handle_msg(Msg, State) of
         ok ->
-            process_msg(More, Parent, State, Options);
+            process_msg(More, Parent, State);
         {ok, NState} ->
-            process_msg(More, Parent, NState, Options);
+            process_msg(More, Parent, NState);
         {ok, Msgs, NState} ->
-            process_msg(append_msg(Msgs, More), Parent, NState, Options);
+            process_msg(append_msg(More, Msgs), Parent, NState);
         {stop, Reason} ->
             terminate(Reason, State);
         {stop, Reason, NState} ->
@@ -289,6 +292,15 @@ process_msg([Msg|More], Parent, State, Options) ->
             terminate(Reason, State)
     end.
 
+-compile({inline, [append_msg/2]}).
+append_msg([], Msgs) when is_list(Msgs) ->
+    Msgs;
+append_msg([], Msg) -> [Msg];
+append_msg(Q, Msgs) when is_list(Msgs) ->
+    lists:append(Q, Msgs);
+append_msg(Q, Msg) ->
+    lists:append(Q, [Msg]).
+
 %%--------------------------------------------------------------------
 %% Handle a Msg
 
@@ -410,18 +422,17 @@ terminate(Reason, State = #state{channel = Channel}) ->
 %%--------------------------------------------------------------------
 %% Sys callbacks
 
-system_continue(Parent, _Deb, {State, Options}) ->
-    recvloop(Parent, State, Options).
+system_continue(Parent, _Debug, State) ->
+    recvloop(Parent, State).
 
-system_terminate(Reason, _Parent, _Deb, {State, _}) ->
+system_terminate(Reason, _Parent, _Debug, State) ->
     terminate(Reason, State).
 
-system_code_change(Misc, _, _, _) ->
-    {ok, Misc}.
-
-system_get_state({State, _Options}) ->
+system_code_change(State, _Mod, _OldVsn, _Extra) ->
     {ok, State}.
 
+system_get_state(State) -> {ok, State}.
+
 %%--------------------------------------------------------------------
 %% Handle call
 
@@ -681,18 +692,13 @@ inc_outgoing_stats(Packet = ?PACKET(Type)) ->
 %%--------------------------------------------------------------------
 %% Helper functions
 
--compile({inline, [append_msg/2]}).
-append_msg(Msgs, Q) when is_list(Msgs) ->
-    lists:append(Msgs, Q);
-append_msg(Msg, Q) -> [Msg|Q].
-
 -compile({inline, [next_msgs/1]}).
 next_msgs(Packet) when is_record(Packet, mqtt_packet) ->
     {outgoing, Packet};
-next_msgs(Action) when is_tuple(Action) ->
-    Action;
-next_msgs(Actions) when is_list(Actions) ->
-    Actions.
+next_msgs(Event) when is_tuple(Event) ->
+    Event;
+next_msgs(More) when is_list(More) ->
+    More.
 
 -compile({inline, [shutdown/2, shutdown/3]}).
 shutdown(Reason, State) ->