diff --git a/apps/emqx/src/emqx_cm_registry_keeper.erl b/apps/emqx/src/emqx_cm_registry_keeper.erl
index f661e203f..1087932df 100644
--- a/apps/emqx/src/emqx_cm_registry_keeper.erl
+++ b/apps/emqx/src/emqx_cm_registry_keeper.erl
@@ -46,12 +46,12 @@ start_link() ->
     gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
 
 init(_) ->
-    case mria_config:whoami() =:= core of
+    case mria_config:whoami() =:= replicant of
         true ->
-            ok = send_delay_start(),
-            {ok, #{next_clientid => undefined}};
+            ignore;
         false ->
-            ignore
+            ok = send_delay_start(),
+            {ok, #{next_clientid => undefined}}
     end.
 
 %% @doc Count the number of sessions.
diff --git a/apps/emqx/test/emqx_cm_registry_keeper_SUITE.erl b/apps/emqx/test/emqx_cm_registry_keeper_SUITE.erl
new file mode 100644
index 000000000..3dcded1c3
--- /dev/null
+++ b/apps/emqx/test/emqx_cm_registry_keeper_SUITE.erl
@@ -0,0 +1,100 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2019-2023 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(emqx_cm_registry_keeper_SUITE).
+
+-compile(export_all).
+-compile(nowarn_export_all).
+
+-include_lib("eunit/include/eunit.hrl").
+-include_lib("snabbkaffe/include/snabbkaffe.hrl").
+-include("emqx_cm.hrl").
+
+%%--------------------------------------------------------------------
+%% CT callbacks
+%%--------------------------------------------------------------------
+
+all() -> emqx_common_test_helpers:all(?MODULE).
+
+init_per_suite(Config) ->
+    AppConfig = "broker.session_history_retain = 2s",
+    Apps = emqx_cth_suite:start(
+        [{emqx, #{config => AppConfig}}],
+        #{work_dir => emqx_cth_suite:work_dir(Config)}
+    ),
+    [{apps, Apps} | Config].
+
+end_per_suite(Config) ->
+    emqx_cth_suite:stop(proplists:get_value(apps, Config)).
+
+init_per_testcase(_TestCase, Config) ->
+    Config.
+
+end_per_testcase(_TestCase, Config) ->
+    Config.
+
+t_cleanup_after_retain(_) ->
+    Pid = spawn(fun() ->
+        receive
+            stop -> ok
+        end
+    end),
+    ClientId = <<"clientid">>,
+    ClientId2 = <<"clientid2">>,
+    emqx_cm_registry:register_channel({ClientId, Pid}),
+    emqx_cm_registry:register_channel({ClientId2, Pid}),
+    ?assertEqual([Pid], emqx_cm_registry:lookup_channels(ClientId)),
+    ?assertEqual([Pid], emqx_cm_registry:lookup_channels(ClientId2)),
+    ?assertEqual(2, emqx_cm_registry_keeper:count(0)),
+    T0 = erlang:system_time(seconds),
+    exit(Pid, kill),
+    %% lookup_channel chesk if the channel is still alive
+    ?assertEqual([], emqx_cm_registry:lookup_channels(ClientId)),
+    ?assertEqual([], emqx_cm_registry:lookup_channels(ClientId2)),
+    %% simulate a DOWN message which causes emqx_cm to call clean_down
+    %% to clean the channels for real
+    ok = emqx_cm:clean_down({Pid, ClientId}),
+    ok = emqx_cm:clean_down({Pid, ClientId2}),
+    ?assertEqual(2, emqx_cm_registry_keeper:count(T0)),
+    ?assertEqual(2, emqx_cm_registry_keeper:count(0)),
+    ?retry(_Interval = 1000, _Attempts = 4, begin
+        ?assertEqual(0, emqx_cm_registry_keeper:count(T0)),
+        ?assertEqual(0, emqx_cm_registry_keeper:count(0))
+    end),
+    ok.
+
+%% count is cached when the number of entries is greater than 1000
+t_count_cache(_) ->
+    Pid = self(),
+    ClientsCount = 999,
+    ClientIds = lists:map(fun erlang:integer_to_binary/1, lists:seq(1, ClientsCount)),
+    Channels = lists:map(fun(ClientId) -> {ClientId, Pid} end, ClientIds),
+    lists:foreach(
+        fun emqx_cm_registry:register_channel/1,
+        Channels
+    ),
+    T0 = erlang:system_time(seconds),
+    ?assertEqual(ClientsCount, emqx_cm_registry_keeper:count(0)),
+    ?assertEqual(ClientsCount, emqx_cm_registry_keeper:count(T0)),
+    %% insert another one to trigger the cache threshold
+    emqx_cm_registry:register_channel({<<"-1">>, Pid}),
+    ?assertEqual(ClientsCount + 1, emqx_cm_registry_keeper:count(0)),
+    ?assertEqual(ClientsCount, emqx_cm_registry_keeper:count(T0)),
+    mnesia:clear_table(?CHAN_REG_TAB),
+    ok.
+
+channel(Id, Pid) ->
+    #channel{chid = Id, pid = Pid}.