diff --git a/apps/emqx_dashboard/src/emqx_dashboard_monitor.erl b/apps/emqx_dashboard/src/emqx_dashboard_monitor.erl
index 7916a6b58..692c7a62e 100644
--- a/apps/emqx_dashboard/src/emqx_dashboard_monitor.erl
+++ b/apps/emqx_dashboard/src/emqx_dashboard_monitor.erl
@@ -40,11 +40,14 @@
 -export([
     samplers/0,
     samplers/2,
-    current_rate/0,
     current_rate/1,
     granularity_adapter/1
 ]).
 
+-ifdef(TEST).
+-export([current_rate_cluster/0]).
+-endif.
+
 %% for rpc
 -export([do_sample/2]).
 
@@ -112,8 +115,33 @@ granularity_adapter(List) when length(List) > 1000 ->
 granularity_adapter(List) ->
     List.
 
+current_rate(all) ->
+    current_rate_cluster();
+current_rate(Node) when Node == node() ->
+    try
+        {ok, Rate} = do_call(current_rate),
+        {ok, Rate}
+    catch
+        _E:R ->
+            ?SLOG(warning, #{msg => "dashboard_monitor_error", reason => R}),
+            %% Rate map 0, ensure api will not crash.
+            %% When joining cluster, dashboard monitor restart.
+            Rate0 = [
+                {Key, 0}
+             || Key <- ?GAUGE_SAMPLER_LIST ++ maps:values(?DELTA_SAMPLER_RATE_MAP)
+            ],
+            {ok, maps:merge(maps:from_list(Rate0), non_rate_value())}
+    end;
+current_rate(Node) ->
+    case emqx_dashboard_proto_v1:current_rate(Node) of
+        {badrpc, Reason} ->
+            {badrpc, {Node, Reason}};
+        {ok, Rate} ->
+            {ok, Rate}
+    end.
+
 %% Get the current rate. Not the current sampler data.
-current_rate() ->
+current_rate_cluster() ->
     Fun =
         fun
             (Node, Cluster) when is_map(Cluster) ->
@@ -133,31 +161,6 @@ current_rate() ->
             {ok, Rate}
     end.
 
-current_rate(all) ->
-    current_rate();
-current_rate(Node) when Node == node() ->
-    try
-        {ok, Rate} = do_call(current_rate),
-        {ok, Rate}
-    catch
-        _E:R ->
-            ?SLOG(warning, #{msg => "dashboard_monitor_error", reason => R}),
-            %% Rate map 0, ensure api will not crash.
-            %% When joining cluster, dashboard monitor restart.
-            Rate0 = [
-                {Key, 0}
-             || Key <- ?GAUGE_SAMPLER_LIST ++ maps:values(?DELTA_SAMPLER_RATE_MAP)
-            ],
-            {ok, maps:from_list(Rate0)}
-    end;
-current_rate(Node) ->
-    case emqx_dashboard_proto_v1:current_rate(Node) of
-        {badrpc, Reason} ->
-            {badrpc, {Node, Reason}};
-        {ok, Rate} ->
-            {ok, Rate}
-    end.
-
 %% -------------------------------------------------------------------------------------------------
 %% gen_server functions
 
@@ -258,8 +261,13 @@ merge_cluster_sampler_map(M1, M2) ->
 merge_cluster_rate(Node, Cluster) ->
     Fun =
         fun
-            (topics, Value, NCluster) ->
-                NCluster#{topics => Value};
+            %% cluster-synced values
+            (topics, V, NCluster) ->
+                NCluster#{topics => V};
+            (retained_msg_count, V, NCluster) ->
+                NCluster#{retained_msg_count => V};
+            (license_quota, V, NCluster) ->
+                NCluster#{license_quota => V};
             (Key, Value, NCluster) ->
                 ClusterValue = maps:get(Key, NCluster, 0),
                 NCluster#{Key => Value + ClusterValue}
diff --git a/apps/emqx_dashboard/src/emqx_dashboard_monitor_api.erl b/apps/emqx_dashboard/src/emqx_dashboard_monitor_api.erl
index 309137362..fc4b171a4 100644
--- a/apps/emqx_dashboard/src/emqx_dashboard_monitor_api.erl
+++ b/apps/emqx_dashboard/src/emqx_dashboard_monitor_api.erl
@@ -151,7 +151,11 @@ monitor_current(get, #{bindings := Bindings}) ->
     RawNode = maps:get(node, Bindings, <<"all">>),
     emqx_utils_api:with_node_or_cluster(RawNode, fun current_rate/1).
 
+-spec current_rate(atom()) ->
+    {error, term()}
+    | {ok, Result :: map()}.
 current_rate(Node) ->
+    %% Node :: 'all' or `NodeName`
     case emqx_dashboard_monitor:current_rate(Node) of
         {badrpc, _} = BadRpc ->
             {error, BadRpc};