fix(monitor api): add ds connections and subscriptions to old counters

Fixes https://emqx.atlassian.net/browse/EMQX-12423
Fixes https://emqx.atlassian.net/browse/EMQX-12267

apps/emqx_dashboard/src/emqx_dashboard_monitor.erl

@@ -264,8 +264,8 @@ merge_cluster_rate(Node, Cluster) ->
             %% cluster-synced values
             (disconnected_durable_sessions, V, NCluster) ->
                 NCluster#{disconnected_durable_sessions => V};
-            (durable_subscriptions, V, NCluster) ->
-                NCluster#{durable_subscriptions => V};
+            (subscriptions_durable, V, NCluster) ->
+                NCluster#{subscriptions_durable => V};
             (topics, V, NCluster) ->
                 NCluster#{topics => V};
             (retained_msg_count, V, NCluster) ->
@@ -281,7 +281,28 @@ merge_cluster_rate(Node, Cluster) ->
                 ClusterValue = maps:get(Key, NCluster, 0),
                 NCluster#{Key => Value + ClusterValue}
         end,
-    maps:fold(Fun, Cluster, Node).
+    Metrics = maps:fold(Fun, Cluster, Node),
+    adjust_synthetic_cluster_metrics(Metrics).
+
+adjust_synthetic_cluster_metrics(Metrics0) ->
+    %% ensure renamed
+    Metrics1 = emqx_utils_maps:rename(durable_subscriptions, subscriptions_durable, Metrics0),
+    DSSubs = maps:get(subscriptions_durable, Metrics1, 0),
+    RamSubs = maps:get(subscriptions, Metrics1, 0),
+    DisconnectedDSs = maps:get(disconnected_durable_sessions, Metrics1, 0),
+    Metrics2 = maps:update_with(
+        subscriptions,
+        fun(Subs) -> Subs + DSSubs end,
+        0,
+        Metrics1
+    ),
+    Metrics = maps:put(subscriptions_ram, RamSubs, Metrics2),
+    maps:update_with(
+        connections,
+        fun(RamConns) -> RamConns + DisconnectedDSs end,
+        DisconnectedDSs,
+        Metrics
+    ).
 
 format({badrpc, Reason}) ->
     {badrpc, Reason};

apps/emqx_dashboard/src/emqx_dashboard_monitor_api.erl

@@ -19,6 +19,7 @@
 -include("emqx_dashboard.hrl").
 -include_lib("typerefl/include/types.hrl").
 -include_lib("hocon/include/hocon_types.hrl").
+-include_lib("emqx_utils/include/emqx_utils_api.hrl").
 
 -behaviour(minirest_api).
 
@@ -159,7 +160,12 @@ dashboard_samplers_fun(Latest) ->
 
 monitor_current(get, #{bindings := Bindings}) ->
     RawNode = maps:get(node, Bindings, <<"all">>),
-    emqx_utils_api:with_node_or_cluster(RawNode, fun current_rate/1).
+    case emqx_utils_api:with_node_or_cluster(RawNode, fun current_rate/1) of
+        ?OK(Rates) ->
+            ?OK(maybe_reject_cluster_only_metrics(RawNode, Rates));
+        Error ->
+            Error
+    end.
 
 -spec current_rate(atom()) ->
     {error, term()}
@@ -242,3 +248,12 @@ swagger_desc_format(Format) ->
 swagger_desc_format(Format, Type) ->
     Interval = emqx_conf:get([dashboard, monitor, interval], ?DEFAULT_SAMPLE_INTERVAL),
     list_to_binary(io_lib:format(Format ++ "~p ~p seconds", [Type, Interval])).
+
+maybe_reject_cluster_only_metrics(<<"all">>, Rates) ->
+    Rates;
+maybe_reject_cluster_only_metrics(_Node, Rates) ->
+    ClusterOnlyMetrics = [
+        durable_subscriptions,
+        disconnected_durable_sessions
+    ],
+    maps:without(ClusterOnlyMetrics, Rates).

apps/emqx_dashboard/test/emqx_dashboard_monitor_SUITE.erl

@@ -196,13 +196,22 @@ t_monitor_current_api(_) ->
     {ok, Rate} = request(["monitor_current"]),
     [
         ?assert(maps:is_key(atom_to_binary(Key, utf8), Rate))
-     || Key <- maps:values(?DELTA_SAMPLER_RATE_MAP) ++ ?GAUGE_SAMPLER_LIST
+     || Key <- maps:values(?DELTA_SAMPLER_RATE_MAP) ++ ?GAUGE_SAMPLER_LIST,
+        %% We rename `durable_subscriptions' key.
+        Key =/= durable_subscriptions
     ],
+    ?assert(maps:is_key(<<"subscriptions_durable">>, Rate)),
+    ?assert(maps:is_key(<<"disconnected_durable_sessions">>, Rate)),
+    ClusterOnlyMetrics = [durable_subscriptions, disconnected_durable_sessions],
     {ok, NodeRate} = request(["monitor_current", "nodes", node()]),
     [
-        ?assert(maps:is_key(atom_to_binary(Key, utf8), NodeRate))
-     || Key <- maps:values(?DELTA_SAMPLER_RATE_MAP) ++ ?GAUGE_SAMPLER_LIST
+        ?assert(maps:is_key(atom_to_binary(Key, utf8), NodeRate), #{key => Key, rates => NodeRate})
+     || Key <- maps:values(?DELTA_SAMPLER_RATE_MAP) ++ ?GAUGE_SAMPLER_LIST,
+        not lists:member(Key, ClusterOnlyMetrics)
     ],
+    ?assertNot(maps:is_key(<<"subscriptions_durable">>, NodeRate)),
+    ?assertNot(maps:is_key(<<"subscriptions_ram">>, NodeRate)),
+    ?assertNot(maps:is_key(<<"disconnected_durable_sessions">>, NodeRate)),
     ok.
 
 t_monitor_current_api_live_connections(_) ->
@@ -290,8 +299,11 @@ t_monitor_reset(_) ->
     {ok, Rate} = request(["monitor_current"]),
     [
         ?assert(maps:is_key(atom_to_binary(Key, utf8), Rate))
-     || Key <- maps:values(?DELTA_SAMPLER_RATE_MAP) ++ ?GAUGE_SAMPLER_LIST
+     || Key <- maps:values(?DELTA_SAMPLER_RATE_MAP) ++ ?GAUGE_SAMPLER_LIST,
+        %% We rename `durable_subscriptions' key.
+        Key =/= durable_subscriptions
     ],
+    ?assert(maps:is_key(<<"subscriptions_durable">>, Rate)),
     {ok, _} =
         snabbkaffe:block_until(
             ?match_n_events(1, #{?snk_kind := dashboard_monitor_flushed}),
@@ -347,8 +359,9 @@ t_persistent_session_stats(_Config) ->
                 %% and non-persistent routes, so we count `commont/topic' twice and get 8
                 %% instead of 6 here.
                 <<"topics">> := 8,
-                <<"durable_subscriptions">> := 4,
-                <<"subscriptions">> := 4
+                <<"subscriptions">> := 8,
+                <<"subscriptions_ram">> := 4,
+                <<"subscriptions_durable">> := 4
             }},
             request(["monitor_current"])
         )
@@ -368,14 +381,15 @@ t_persistent_session_stats(_Config) ->
     ?retry(1_000, 10, begin
         ?assertMatch(
             {ok, #{
-                <<"connections">> := 1,
+                <<"connections">> := 2,
                 <<"disconnected_durable_sessions">> := 1,
                 %% N.B.: we currently don't perform any deduplication between persistent
                 %% and non-persistent routes, so we count `commont/topic' twice and get 8
                 %% instead of 6 here.
                 <<"topics">> := 8,
-                <<"durable_subscriptions">> := 4,
-                <<"subscriptions">> := 4
+                <<"subscriptions">> := 8,
+                <<"subscriptions_ram">> := 4,
+                <<"subscriptions_durable">> := 4
             }},
             request(["monitor_current"])
         )