feat(stats): track live / connected channel count for monitoring

In order to correctly display the number of connected clients in our
monitor dashboard, we need to track those connections that are
actually connected to clients, not considering connections from
persistent sessions that are disconnected.  Today, the
`connections.count` that is displayed in the dashboards considers
those disconnected persistent sessions as well.

src/emqx_channel.erl

@@ -1536,6 +1536,8 @@ ensure_connected(Channel = #channel{conninfo = ConnInfo,
                                     clientinfo = ClientInfo}) ->
     NConnInfo = ConnInfo#{connected_at => erlang:system_time(millisecond)},
     ok = run_hooks('client.connected', [ClientInfo, NConnInfo]),
+    ChanPid = self(),
+    emqx_cm:mark_channel_connected(ChanPid),
     Channel#channel{conninfo   = NConnInfo,
                     conn_state = connected
                    }.
@@ -1624,6 +1626,8 @@ ensure_disconnected(Reason, Channel = #channel{conninfo = ConnInfo,
                                                clientinfo = ClientInfo}) ->
     NConnInfo = ConnInfo#{disconnected_at => erlang:system_time(millisecond)},
     ok = run_hooks('client.disconnected', [ClientInfo, Reason, NConnInfo]),
+    ChanPid = self(),
+    emqx_cm:mark_channel_disconnected(ChanPid),
     Channel#channel{conninfo = NConnInfo, conn_state = disconnected}.
 
 %%--------------------------------------------------------------------
@@ -1725,4 +1729,3 @@ flag(false) -> 0.
 set_field(Name, Value, Channel) ->
     Pos = emqx_misc:index_of(Name, record_info(fields, channel)),
     setelement(Pos+1, Channel, Value).
-

src/emqx_cm.erl

@@ -22,6 +22,7 @@
 -include("emqx.hrl").
 -include("logger.hrl").
 -include("types.hrl").
+-include_lib("stdlib/include/ms_transform.hrl").
 -include_lib("snabbkaffe/include/snabbkaffe.hrl").
 
 -logger_header("[CM]").
@@ -72,7 +73,12 @@
         ]).
 
 %% Internal export
--export([stats_fun/0, clean_down/1]).
+-export([ stats_fun/0
+        , clean_down/1
+        , mark_channel_connected/1
+        , mark_channel_disconnected/1
+        , get_connected_client_count/0
+        ]).
 
 -type(chan_pid() :: pid()).
 
@@ -80,11 +86,13 @@
 -define(CHAN_TAB, emqx_channel).
 -define(CHAN_CONN_TAB, emqx_channel_conn).
 -define(CHAN_INFO_TAB, emqx_channel_info).
+-define(CHAN_LIVE_TAB, emqx_channel_live).
 
 -define(CHAN_STATS,
         [{?CHAN_TAB, 'channels.count', 'channels.max'},
          {?CHAN_TAB, 'sessions.count', 'sessions.max'},
-         {?CHAN_CONN_TAB, 'connections.count', 'connections.max'}
+         {?CHAN_CONN_TAB, 'connections.count', 'connections.max'},
+         {?CHAN_LIVE_TAB, 'live_connections.count', 'live_connections.max'}
         ]).
 
 %% Batch drain
@@ -437,8 +445,10 @@ init([]) ->
     ok = emqx_tables:new(?CHAN_TAB, [bag, {read_concurrency, true}|TabOpts]),
     ok = emqx_tables:new(?CHAN_CONN_TAB, [bag | TabOpts]),
     ok = emqx_tables:new(?CHAN_INFO_TAB, [set, compressed | TabOpts]),
+    ok = emqx_tables:new(?CHAN_LIVE_TAB, [set, {write_concurrency, true} | TabOpts]),
     ok = emqx_stats:update_interval(chan_stats, fun ?MODULE:stats_fun/0),
-    {ok, #{chan_pmon => emqx_pmon:new()}}.
+    State = #{chan_pmon => emqx_pmon:new()},
+    {ok, State}.
 
 handle_call(Req, _From, State) ->
     ?LOG(error, "Unexpected call: ~p", [Req]),
@@ -447,17 +457,21 @@ handle_call(Req, _From, State) ->
 handle_cast({registered, {ClientId, ChanPid}}, State = #{chan_pmon := PMon}) ->
     PMon1 = emqx_pmon:monitor(ChanPid, ClientId, PMon),
     {noreply, State#{chan_pmon := PMon1}};
-
 handle_cast(Msg, State) ->
     ?LOG(error, "Unexpected cast: ~p", [Msg]),
     {noreply, State}.
 
 handle_info({'DOWN', _MRef, process, Pid, _Reason}, State = #{chan_pmon := PMon}) ->
+    ?tp(emqx_cm_process_down, #{pid => Pid, reason => _Reason}),
     ChanPids = [Pid | emqx_misc:drain_down(?BATCH_SIZE)],
     {Items, PMon1} = emqx_pmon:erase_all(ChanPids, PMon),
+    lists:foreach(
+      fun({ChanPid, _ClientID}) ->
+              mark_channel_disconnected(ChanPid)
+      end,
+      Items),
     ok = emqx_pool:async_submit(fun lists:foreach/2, [fun ?MODULE:clean_down/1, Items]),
     {noreply, State#{chan_pmon := PMon1}};
-
 handle_info(Info, State) ->
     ?LOG(error, "Unexpected info: ~p", [Info]),
     {noreply, State}.
@@ -493,3 +507,18 @@ get_chann_conn_mod(ClientId, ChanPid) when node(ChanPid) == node() ->
 get_chann_conn_mod(ClientId, ChanPid) ->
     rpc_call(node(ChanPid), get_chann_conn_mod, [ClientId, ChanPid], ?T_GET_INFO).
 
+mark_channel_connected(ChanPid) ->
+    ?tp(emqx_cm_connected_client_count_inc, #{}),
+    ets:insert_new(?CHAN_LIVE_TAB, {ChanPid, true}),
+    ok.
+
+mark_channel_disconnected(ChanPid) ->
+    ?tp(emqx_cm_connected_client_count_dec, #{}),
+    ets:delete(?CHAN_LIVE_TAB, ChanPid),
+    ok.
+
+get_connected_client_count() ->
+    case ets:info(?CHAN_LIVE_TAB, size) of
+        undefined -> 0;
+        Size -> Size
+    end.

src/emqx_connection.erl

@@ -518,7 +518,7 @@ terminate(Reason, State = #state{channel = Channel, transport = Transport,
             ?tp(warning, unclean_terminate, #{exception => E, context => C, stacktrace => S})
     end,
     ?tp(info, terminate, #{reason => Reason}),
-    maybe_raise_excption(Reason).
+    maybe_raise_exception(Reason).
 
 %% close socket, discard new state, always return ok.
 close_socket_ok(State) ->
@@ -526,12 +526,12 @@ close_socket_ok(State) ->
     ok.
 
 %% tell truth about the original exception
-maybe_raise_excption(#{exception := Exception,
+maybe_raise_exception(#{exception := Exception,
                        context := Context,
                        stacktrace := Stacktrace
                       }) ->
     erlang:raise(Exception, Context, Stacktrace);
-maybe_raise_excption(Reason) ->
+maybe_raise_exception(Reason) ->
     exit(Reason).
 
 %%--------------------------------------------------------------------

src/emqx_stats.erl

@@ -21,6 +21,7 @@
 -include("emqx.hrl").
 -include("logger.hrl").
 -include("types.hrl").
+-include_lib("snabbkaffe/include/snabbkaffe.hrl").
 
 -logger_header("[Stats]").
 
@@ -67,8 +68,10 @@
 
 %% Connection stats
 -define(CONNECTION_STATS,
-        ['connections.count', %% Count of Concurrent Connections
+        [ 'connections.count' %% Count of Concurrent Connections
-         'connections.max'    %% Maximum Number of Concurrent Connections
+        , 'connections.max'   %% Maximum Number of Concurrent Connections
+        , 'live_connections.count' %% Count of connected clients
+        , 'live_connections.max' %% Maximum number of connected clients
         ]).
 
 %% Channel stats
@@ -216,6 +219,11 @@ handle_cast({setstat, Stat, MaxStat, Val}, State) ->
             ets:insert(?TAB, {MaxStat, Val})
     end,
     safe_update_element(Stat, Val),
+    ?tp(emqx_stats_setstat,
+        #{ count_stat => Stat
+         , max_stat => MaxStat
+         , value => Val
+         }),
     {noreply, State};
 
 handle_cast({update_interval, Update = #update{name = Name}},
@@ -274,4 +282,3 @@ safe_update_element(Key, Val) ->
         error:badarg ->
             ?LOG(warning, "Failed to update ~0p to ~0p", [Key, Val])
     end.
-

test/emqx_broker_SUITE.erl

@@ -23,20 +23,63 @@
 
 -include_lib("eunit/include/eunit.hrl").
 -include_lib("common_test/include/ct.hrl").
+-include_lib("snabbkaffe/include/snabbkaffe.hrl").
 
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/emqx_mqtt.hrl").
 
-all() -> emqx_ct:all(?MODULE).
+all() ->
+    [ {group, all_cases}
+    , {group, connected_client_count_group}
+    ].
 
-init_per_suite(Config) ->
+groups() ->
+    TCs = emqx_ct:all(?MODULE),
+    ConnClientTCs = [ t_connected_client_count_persistent
+                    , t_connected_client_count_anonymous
+                    , t_connected_client_stats
+                    ],
+    OtherTCs = TCs -- ConnClientTCs,
+    [ {all_cases, [], OtherTCs}
+    , {connected_client_count_group, [ {group, tcp}
+                                     , {group, ws}
+                                     ]}
+    , {tcp, [], ConnClientTCs}
+    , {ws, [], ConnClientTCs}
+    ].
+
+init_per_group(connected_client_count_group, Config) ->
+    Config;
+init_per_group(tcp, Config) ->
+    emqx_ct_helpers:boot_modules(all),
+    emqx_ct_helpers:start_apps([]),
+    [{conn_fun, connect} | Config];
+init_per_group(ws, Config) ->
+    emqx_ct_helpers:boot_modules(all),
+    emqx_ct_helpers:start_apps([]),
+    [ {ssl, false}
+    , {enable_websocket, true}
+    , {conn_fun, ws_connect}
+    , {port, 8083}
+    , {host, "localhost"}
+    | Config
+    ];
+init_per_group(_Group, Config) ->
     emqx_ct_helpers:boot_modules(all),
     emqx_ct_helpers:start_apps([]),
     Config.
 
-end_per_suite(_Config) ->
+end_per_group(connected_client_count_group, _Config) ->
+    ok;
+end_per_group(_Group, _Config) ->
     emqx_ct_helpers:stop_apps([]).
 
+init_per_suite(Config) ->
+    Config.
+
+end_per_suite(_Config) ->
+    ok.
+
 init_per_testcase(Case, Config) ->
     ?MODULE:Case({init, Config}).
 
@@ -277,6 +320,248 @@ t_stats_fun({'end', _Config}) ->
     ok = emqx_broker:unsubscribe(<<"topic">>),
     ok = emqx_broker:unsubscribe(<<"topic2">>).
 
+%% persistent sessions, when gone, do not contribute to connected
+%% client count
+t_connected_client_count_persistent({init, Config}) ->
+    ok = snabbkaffe:start_trace(),
+    process_flag(trap_exit, true),
+    Config;
+t_connected_client_count_persistent(Config) when is_list(Config) ->
+    ConnFun = ?config(conn_fun, Config),
+    ClientID = <<"clientid">>,
+    ?assertEqual(0, emqx_cm:get_connected_client_count()),
+    {ok, ConnPid0} = emqtt:start_link([ {clean_start, false}
+                                      , {clientid, ClientID}
+                                      | Config]),
+    {{ok, _}, {ok, [_]}} = wait_for_events(
+                             fun() -> emqtt:ConnFun(ConnPid0) end,
+                             [emqx_cm_connected_client_count_inc]
+                            ),
+    ?assertEqual(1, emqx_cm:get_connected_client_count()),
+    {ok, {ok, [_]}} = wait_for_events(
+                        fun() -> emqtt:disconnect(ConnPid0) end,
+                        [emqx_cm_connected_client_count_dec]
+                       ),
+    ?assertEqual(0, emqx_cm:get_connected_client_count()),
+    %% reconnecting
+    {ok, ConnPid1} = emqtt:start_link([ {clean_start, false}
+                                      , {clientid, ClientID}
+                                      | Config
+                                      ]),
+    {{ok, _}, {ok, [_]}} = wait_for_events(
+                             fun() -> emqtt:ConnFun(ConnPid1) end,
+                             [emqx_cm_connected_client_count_inc]
+                            ),
+    ?assertEqual(1, emqx_cm:get_connected_client_count()),
+    %% taking over
+    {ok, ConnPid2} = emqtt:start_link([ {clean_start, false}
+                                      , {clientid, ClientID}
+                                      | Config
+                                      ]),
+    {{ok, _}, {ok, [_, _]}} = wait_for_events(
+                             fun() -> emqtt:ConnFun(ConnPid2) end,
+                             [ emqx_cm_connected_client_count_inc
+                             , emqx_cm_connected_client_count_dec
+                             ],
+                             500
+                            ),
+    ?assertEqual(1, emqx_cm:get_connected_client_count()),
+    %% abnormal exit of channel process
+    ChanPids = emqx_cm:all_channels(),
+    {ok, {ok, [_, _]}} = wait_for_events(
+                           fun() ->
+                                   lists:foreach(
+                                     fun(ChanPid) -> exit(ChanPid, kill) end,
+                                     ChanPids)
+                           end,
+                           [ emqx_cm_connected_client_count_dec
+                           , emqx_cm_process_down
+                           ]
+                          ),
+    ?assertEqual(0, emqx_cm:get_connected_client_count()),
+    ok;
+t_connected_client_count_persistent({'end', _Config}) ->
+    snabbkaffe:stop(),
+    ok.
+
+%% connections without client_id also contribute to connected client
+%% count
+t_connected_client_count_anonymous({init, Config}) ->
+    ok = snabbkaffe:start_trace(),
+    process_flag(trap_exit, true),
+    Config;
+t_connected_client_count_anonymous(Config) when is_list(Config) ->
+    ConnFun = ?config(conn_fun, Config),
+    ?assertEqual(0, emqx_cm:get_connected_client_count()),
+    %% first client
+    {ok, ConnPid0} = emqtt:start_link([ {clean_start, true}
+                                      | Config]),
+    {{ok, _}, {ok, [_]}} = wait_for_events(
+                             fun() -> emqtt:ConnFun(ConnPid0) end,
+                             [emqx_cm_connected_client_count_inc]
+                            ),
+    ?assertEqual(1, emqx_cm:get_connected_client_count()),
+    %% second client
+    {ok, ConnPid1} = emqtt:start_link([ {clean_start, true}
+                                      | Config]),
+    {{ok, _}, {ok, [_]}} = wait_for_events(
+                             fun() -> emqtt:ConnFun(ConnPid1) end,
+                             [emqx_cm_connected_client_count_inc]
+                            ),
+    ?assertEqual(2, emqx_cm:get_connected_client_count()),
+    %% when first client disconnects, shouldn't affect the second
+    {ok, {ok, [_, _]}} = wait_for_events(
+                        fun() -> emqtt:disconnect(ConnPid0) end,
+                        [ emqx_cm_connected_client_count_dec
+                        , emqx_cm_process_down
+                        ]
+                       ),
+    ?assertEqual(1, emqx_cm:get_connected_client_count()),
+    %% reconnecting
+    {ok, ConnPid2} = emqtt:start_link([ {clean_start, true}
+                                      | Config
+                                      ]),
+    {{ok, _}, {ok, [_]}} = wait_for_events(
+                             fun() -> emqtt:ConnFun(ConnPid2) end,
+                             [emqx_cm_connected_client_count_inc]
+                            ),
+    ?assertEqual(2, emqx_cm:get_connected_client_count()),
+    {ok, {ok, [_, _]}} = wait_for_events(
+                           fun() -> emqtt:disconnect(ConnPid1) end,
+                           [ emqx_cm_connected_client_count_dec
+                           , emqx_cm_process_down
+                           ]
+                          ),
+    ?assertEqual(1, emqx_cm:get_connected_client_count()),
+    %% abnormal exit of channel process
+    Chans = emqx_cm:all_channels(),
+    {ok, {ok, [_, _]}} = wait_for_events(
+                           fun() ->
+                                   lists:foreach(
+                                     fun(ChanPid) -> exit(ChanPid, kill) end,
+                                     Chans)
+                           end,
+                           [ emqx_cm_connected_client_count_dec
+                           , emqx_cm_process_down
+                           ]
+                          ),
+    ?assertEqual(0, emqx_cm:get_connected_client_count()),
+    ok;
+t_connected_client_count_anonymous({'end', _Config}) ->
+    snabbkaffe:stop(),
+    ok.
+
+t_connected_client_stats({init, Config}) ->
+    ok = supervisor:terminate_child(emqx_kernel_sup, emqx_stats),
+    {ok, _} = supervisor:restart_child(emqx_kernel_sup, emqx_stats),
+    ok = snabbkaffe:start_trace(),
+    Config;
+t_connected_client_stats(Config) when is_list(Config) ->
+    ConnFun = ?config(conn_fun, Config),
+    ?assertEqual(0, emqx_cm:get_connected_client_count()),
+    ?assertEqual(0, emqx_stats:getstat('live_connections.count')),
+    ?assertEqual(0, emqx_stats:getstat('live_connections.max')),
+    {ok, ConnPid} = emqtt:start_link([ {clean_start, true}
+                                     , {clientid, <<"clientid">>}
+                                     | Config
+                                     ]),
+    {{ok, _}, {ok, [_]}} = wait_for_events(
+                             fun() -> emqtt:ConnFun(ConnPid) end,
+                             [emqx_cm_connected_client_count_inc]
+                            ),
+    %% ensure stats are synchronized
+    {_, {ok, [_]}} = wait_for_stats(
+                       fun emqx_cm:stats_fun/0,
+                       [#{count_stat => 'live_connections.count',
+                          max_stat => 'live_connections.max'}]
+                      ),
+    ?assertEqual(1, emqx_stats:getstat('live_connections.count')),
+    ?assertEqual(1, emqx_stats:getstat('live_connections.max')),
+    {ok, {ok, [_]}} = wait_for_events(
+                        fun() -> emqtt:disconnect(ConnPid) end,
+                        [emqx_cm_connected_client_count_dec]
+                       ),
+    %% ensure stats are synchronized
+    {_, {ok, [_]}} = wait_for_stats(
+                       fun emqx_cm:stats_fun/0,
+                       [#{count_stat => 'live_connections.count',
+                          max_stat => 'live_connections.max'}]
+                      ),
+    ?assertEqual(0, emqx_stats:getstat('live_connections.count')),
+    ?assertEqual(1, emqx_stats:getstat('live_connections.max')),
+    ok;
+t_connected_client_stats({'end', _Config}) ->
+    ok = snabbkaffe:stop(),
+    ok = supervisor:terminate_child(emqx_kernel_sup, emqx_stats),
+    {ok, _} = supervisor:restart_child(emqx_kernel_sup, emqx_stats),
+    ok.
+
+%% the count must be always non negative
+t_connect_client_never_negative({init, Config}) ->
+    Config;
+t_connect_client_never_negative(Config) when is_list(Config) ->
+    ?assertEqual(0, emqx_cm:get_connected_client_count()),
+    %% would go to -1
+    ChanPid = list_to_pid("<0.0.1>"),
+    emqx_cm:mark_channel_disconnected(ChanPid),
+    ?assertEqual(0, emqx_cm:get_connected_client_count()),
+    %% would be 0, if really went to -1
+    emqx_cm:mark_channel_connected(ChanPid),
+    ?assertEqual(1, emqx_cm:get_connected_client_count()),
+    ok;
+t_connect_client_never_negative({'end', _Config}) ->
+    ok.
+
+wait_for_events(Action, Kinds) ->
+    wait_for_events(Action, Kinds, 500).
+
+wait_for_events(Action, Kinds, Timeout) ->
+    Predicate = fun(#{?snk_kind := K}) ->
+                        lists:member(K, Kinds)
+                end,
+    N = length(Kinds),
+    {ok, Sub} = snabbkaffe_collector:subscribe(Predicate, N, Timeout, 0),
+    Res = Action(),
+    case snabbkaffe_collector:receive_events(Sub) of
+        {timeout, _} ->
+            {Res, timeout};
+        {ok, Events} ->
+            {Res, {ok, Events}}
+    end.
+
+wait_for_stats(Action, Stats) ->
+    Predicate = fun(Event = #{?snk_kind := emqx_stats_setstat}) ->
+                        Stat = maps:with(
+                                 [ count_stat
+                                 , max_stat
+                                 ], Event),
+                        lists:member(Stat, Stats);
+                   (_) ->
+                        false
+                end,
+    N = length(Stats),
+    Timeout = 500,
+    {ok, Sub} = snabbkaffe_collector:subscribe(Predicate, N, Timeout, 0),
+    Res = Action(),
+    case snabbkaffe_collector:receive_events(Sub) of
+        {timeout, _} ->
+            {Res, timeout};
+        {ok, Events} ->
+            {Res, {ok, Events}}
+    end.
+
+insert_fake_channels() ->
+    %% Insert copies to simulate missed counts
+    Tab = emqx_channel_info,
+    Key = ets:first(Tab),
+    [{_Chan, ChanInfo = #{conn_state := connected}, Stats}] = ets:lookup(Tab, Key),
+    ets:insert(Tab, [ {{"fake" ++ integer_to_list(N), undefined}, ChanInfo, Stats}
+                     || N <- lists:seq(1, 9)]),
+    %% these should not be counted
+    ets:insert(Tab, [ { {"fake" ++ integer_to_list(N), undefined}
+                      , ChanInfo#{conn_state := disconnected}, Stats}
+                     || N <- lists:seq(10, 20)]).
+
 recv_msgs(Count) ->
     recv_msgs(Count, []).
 

test/emqx_channel_SUITE.erl

@@ -33,6 +33,8 @@ all() -> emqx_ct:all(?MODULE).
 init_per_suite(Config) ->
     %% CM Meck
     ok = meck:new(emqx_cm, [passthrough, no_history, no_link]),
+    ok = meck:expect(emqx_cm, mark_channel_connected, fun(_) -> ok end),
+    ok = meck:expect(emqx_cm, mark_channel_disconnected, fun(_) -> ok end),
     %% Access Control Meck
     ok = meck:new(emqx_access_control, [passthrough, no_history, no_link]),
     ok = meck:expect(emqx_access_control, authenticate,
@@ -835,4 +837,3 @@ session(InitFields) when is_map(InitFields) ->
 quota() ->
     emqx_limiter:init(zone, [{conn_messages_routing, {5, 1}},
                              {overall_messages_routing, {10, 1}}]).
-

test/emqx_connection_SUITE.erl

@@ -36,6 +36,8 @@ init_per_suite(Config) ->
     ok = meck:new(emqx_channel, [passthrough, no_history, no_link]),
     %% Meck Cm
     ok = meck:new(emqx_cm, [passthrough, no_history, no_link]),
+    ok = meck:expect(emqx_cm, mark_channel_connected, fun(_) -> ok end),
+    ok = meck:expect(emqx_cm, mark_channel_disconnected, fun(_) -> ok end),
     %% Meck Limiter
     ok = meck:new(emqx_limiter, [passthrough, no_history, no_link]),
     %% Meck Pd

test/emqx_mqueue_SUITE.erl

@@ -121,7 +121,7 @@ t_priority_mqueue(_) ->
     ?assertEqual(5, ?Q:len(Q5)),
     {_, Q6} = ?Q:in(#message{qos = 1, topic = <<"t2">>}, Q5),
     ?assertEqual(5, ?Q:len(Q6)),
-    {{value, Msg}, Q7} = ?Q:out(Q6),
+    {{value, _Msg}, Q7} = ?Q:out(Q6),
     ?assertEqual(4, ?Q:len(Q7)).
 
 t_priority_mqueue_conservation(_) ->

test/emqx_ws_connection_SUITE.erl

@@ -48,6 +48,10 @@ init_per_testcase(TestCase, Config) when
     TestCase =/= t_ws_pingreq_before_connected,
     TestCase =/= t_ws_non_check_origin
     ->
+    %% Meck Cm
+    ok = meck:new(emqx_cm, [passthrough, no_history, no_link]),
+    ok = meck:expect(emqx_cm, mark_channel_connected, fun(_) -> ok end),
+    ok = meck:expect(emqx_cm, mark_channel_disconnected, fun(_) -> ok end),
     %% Mock cowboy_req
     ok = meck:new(cowboy_req, [passthrough, no_history, no_link]),
     ok = meck:expect(cowboy_req, header, fun(_, _, _) -> <<>> end),
@@ -95,7 +99,8 @@ end_per_testcase(TestCase, _Config) when
         TestCase =/= t_ws_pingreq_before_connected
         ->
     lists:foreach(fun meck:unload/1,
-                  [cowboy_req,
+                  [emqx_cm,
+                   cowboy_req,
                    emqx_zone,
                    emqx_access_control,
                    emqx_broker,
@@ -389,14 +394,12 @@ t_handle_info_close(_) ->
     {[{close, _}], _St} = ?ws_conn:handle_info({close, protocol_error}, st()).
 
 t_handle_info_event(_) ->
-    ok = meck:new(emqx_cm, [passthrough, no_history]),
     ok = meck:expect(emqx_cm, register_channel, fun(_,_,_) -> ok end),
     ok = meck:expect(emqx_cm, insert_channel_info, fun(_,_,_) -> ok end),
     ok = meck:expect(emqx_cm, connection_closed, fun(_) -> true end),
     {ok, _} = ?ws_conn:handle_info({event, connected}, st()),
     {ok, _} = ?ws_conn:handle_info({event, disconnected}, st()),
-    {ok, _} = ?ws_conn:handle_info({event, updated}, st()),
+    {ok, _} = ?ws_conn:handle_info({event, updated}, st()).
-    ok = meck:unload(emqx_cm).
 
 t_handle_timeout_idle_timeout(_) ->
     TRef = make_ref(),