diff --git a/etc/emqx.conf b/etc/emqx.conf
index d41d604c3..82ec0dc8c 100644
--- a/etc/emqx.conf
+++ b/etc/emqx.conf
@@ -29,7 +29,7 @@ cluster.proto_dist = inet_tcp
 ## - mcast:  IP Multicast
 ## - dns:    DNS A Record
 ## - etcd:   etcd
-## - k8s:    Kubernates
+## - k8s:    Kubernetes
 ##
 ## Default: manual
 cluster.discovery = manual
@@ -141,9 +141,9 @@ cluster.autoclean = 5m
 ## cluster.etcd.ssl.cacertfile = {{ platform_etc_dir }}/certs/ca.pem
 
 ##--------------------------------------------------------------------
-## Cluster using Kubernates
+## Cluster using Kubernetes
 
-## Kubernates API server list, seperated by ','.
+## Kubernetes API server list, seperated by ','.
 ##
 ## Value: String
 ## cluster.k8s.apiserver = http://10.110.111.204:8080
@@ -168,7 +168,7 @@ cluster.autoclean = 5m
 ## Value: String
 ## cluster.k8s.suffix = pod.cluster.local
 
-## Kubernates Namespace
+## Kubernetes Namespace
 ##
 ## Value: String
 ## cluster.k8s.namespace = default
@@ -849,6 +849,11 @@ zone.internal.ignore_loop_deliver = false
 ## Value: true | false
 zone.internal.strict_mode = false
 
+## Allow the zone's clients to bypass authentication step
+##
+## Value: true | false
+zone.internal.bypass_auth_plugins = true
+
 ##--------------------------------------------------------------------
 ## Listeners
 ##--------------------------------------------------------------------
diff --git a/priv/emqx.schema b/priv/emqx.schema
index 468dfc343..db4421c91 100644
--- a/priv/emqx.schema
+++ b/priv/emqx.schema
@@ -939,6 +939,12 @@ end}.
   {datatype, {enum, [true, false]}}
 ]}.
 
+%% @doc Whether to bypass the authentication step
+{mapping, "zone.$name.bypass_auth_plugins", "emqx.zones", [
+  {default, false},
+  {datatype, {enum, [true, false]}}
+]}.
+
 {translation, "emqx.zones", fun(Conf) ->
   Mapping = fun("publish_limit", Val) ->
                     [L, D] = string:tokens(Val, ", "),
diff --git a/src/emqx_access_control.erl b/src/emqx_access_control.erl
index 4ee62a42e..e891ca275 100644
--- a/src/emqx_access_control.erl
+++ b/src/emqx_access_control.erl
@@ -34,11 +34,12 @@
 
 -spec(authenticate(emqx_types:clientinfo()) -> {ok, result()} | {error, term()}).
 authenticate(ClientInfo = #{zone := Zone}) ->
-    case run_hooks('client.authenticate', [ClientInfo], default_auth_result(Zone)) of
-        Result = #{auth_result := success} ->
-            {ok, Result};
-	    Result ->
-            {error, maps:get(auth_result, Result, unknown_error)}
+    AuthResult = default_auth_result(Zone),
+    case emqx_zone:get_env(Zone, bypass_auth_plugins, false) of
+        true ->
+            return_auth_result(AuthResult);
+        false ->
+            return_auth_result(run_hooks('client.authenticate', [ClientInfo], AuthResult))
     end.
 
 %% @doc Check ACL
@@ -81,3 +82,8 @@ default_auth_result(Zone) ->
 run_hooks(Name, Args, Acc) ->
     ok = emqx_metrics:inc(Name), emqx_hooks:run_fold(Name, Args, Acc).
 
+-compile({inline, [return_auth_result/1]}).
+return_auth_result(Result = #{auth_result := success}) ->
+    {ok, Result};
+return_auth_result(Result) ->
+    {error, maps:get(auth_result, Result, unknown_error)}.
diff --git a/src/emqx_cm.erl b/src/emqx_cm.erl
index 8bc2fbd07..dd8b02e54 100644
--- a/src/emqx_cm.erl
+++ b/src/emqx_cm.erl
@@ -273,6 +273,8 @@ discard_session(ClientId) when is_binary(ClientId) ->
                       try
                           discard_session(ClientId, ChanPid)
                       catch
+                          _:{noproc,_}:_Stk -> ok;
+                          _:{{shutdown,_},_}:_Stk -> ok;
                           _:Error:_Stk ->
                               ?LOG(error, "Failed to discard ~p: ~p", [ChanPid, Error])
                       end
diff --git a/src/emqx_json.erl b/src/emqx_json.erl
index c81c9b06b..93243f7ac 100644
--- a/src/emqx_json.erl
+++ b/src/emqx_json.erl
@@ -103,7 +103,7 @@ safe_decode(Json, Opts) ->
           , from_ejson/1
           ]}).
 
-to_ejson([[{_,_}]|_] = L) ->
+to_ejson([[{_,_}|_]|_] = L) ->
     [to_ejson(E) || E <- L];
 to_ejson([{_, _}|_] = L) ->
     lists:foldl(
diff --git a/test/emqx_access_control_SUITE.erl b/test/emqx_access_control_SUITE.erl
index 34a0b83b1..ca4db1fbb 100644
--- a/test/emqx_access_control_SUITE.erl
+++ b/test/emqx_access_control_SUITE.erl
@@ -52,6 +52,20 @@ t_check_acl(_) ->
 t_reload_acl(_) ->
     ?assertEqual(ok, emqx_access_control:reload_acl()).
 
+t_bypass_auth_plugins(_) ->
+    AuthFun = fun(#{zone := bypass_zone}, AuthRes) ->
+                      {stop, AuthRes#{auth_result => password_error}};
+                 (#{zone := _}, AuthRes) ->
+                      {stop, AuthRes#{auth_result => success}}
+              end,
+    ClientInfo = clientinfo(),
+    emqx_zone:set_env(bypass_zone, allow_anonymous, true),
+    emqx_zone:set_env(zone, allow_anonymous, false),
+    emqx_zone:set_env(bypass_zone, bypass_auth_plugins, true),
+    emqx:hook('client.authenticate', AuthFun, []),
+    ?assertMatch({ok, _}, emqx_access_control:authenticate(ClientInfo#{zone => bypass_zone})),
+    ?assertMatch({ok, _}, emqx_access_control:authenticate(ClientInfo)).
+
 %%--------------------------------------------------------------------
 %% Helper functions
 %%--------------------------------------------------------------------
diff --git a/test/emqx_json_SUITE.erl b/test/emqx_json_SUITE.erl
index 434180cb9..67f8108c5 100644
--- a/test/emqx_json_SUITE.erl
+++ b/test/emqx_json_SUITE.erl
@@ -68,6 +68,11 @@ t_decode_encode(_) ->
     [{<<"foo">>, <<"bar">>}] = decode(encode({[{<<"foo">>, <<"bar">>}]})),
     [{<<"foo">>, <<"bar">>}] = decode(encode([{<<"foo">>, <<"bar">>}])),
     [[{<<"foo">>, <<"bar">>}]] = decode(encode([[{<<"foo">>, <<"bar">>}]])),
+    [[{<<"foo">>, <<"bar">>},
+      {<<"a">>, <<"b">>}],
+     [{<<"x">>, <<"y">>}]] = decode(encode([[{<<"foo">>, <<"bar">>},
+                                             {<<"a">>, <<"b">>}],
+                                            [{<<"x">>, <<"y">>}]])),
     #{<<"foo">> := <<"bar">>} = decode(encode(#{<<"foo">> => <<"bar">>}), [return_maps]),
     JsonText = <<"{\"bool\":true,\"int\":10,\"foo\":\"bar\"}">>,
     JsonMaps = #{<<"bool">> => true,
diff --git a/test/emqx_logger_formatter_SUITE.erl b/test/emqx_logger_formatter_SUITE.erl
index 6699ae68c..3d7469dca 100644
--- a/test/emqx_logger_formatter_SUITE.erl
+++ b/test/emqx_logger_formatter_SUITE.erl
@@ -20,6 +20,7 @@
 -module(emqx_logger_formatter_SUITE).
 
 -compile(export_all).
+-compile(nowarn_export_all).
 
 -include_lib("eunit/include/eunit.hrl").
 -include_lib("common_test/include/ct.hrl").