Merge pull request #3111 from emqx/issue#3109

Fix issue#3109 - remove the 'sessions.persistent.count', 'sessions.persistent.max' stats

src/emqx_stats.erl

@@ -58,7 +58,7 @@
 -record(update, {name, countdown, interval, func}).
 
 -record(state, {
-          timer :: reference(),
+          timer   :: reference(),
           updates :: [#update{}],
           tick_ms :: timeout()
          }).
@@ -66,48 +66,53 @@
 -type(stats() :: list({atom(), non_neg_integer()})).
 
 %% Connection stats
--define(CONNECTION_STATS, [
-    'connections.count', % current connections
-    'connections.max'    % maximum connections connected
-]).
+-define(CONNECTION_STATS,
+        ['connections.count', %% Count of Concurrent Connections
+         'connections.max'    %% Maximum Number of Concurrent Connections
+        ]).
+
+%% Channel stats
+-define(CHANNEL_STATS,
+        ['channels.count', %% Count of Concurrent Channels
+         'channels.max'    %% Maximum Number of Concurrent Channels
+        ]).
 
 %% Session stats
--define(SESSION_STATS, [
-    'sessions.count',
-    'sessions.max',
-    'sessions.persistent.count',
-    'sessions.persistent.max'
-]).
+-define(SESSION_STATS,
+        ['sessions.count', %% Count of Concurrent Sessions
+         'sessions.max'    %% Maximum Number of Concurrent Sessions
+        ]).
 
-%% Subscribers, Subscriptions stats
--define(PUBSUB_STATS, [
-    'topics.count',
-    'topics.max',
-    'suboptions.count',
-    'suboptions.max',
-    'subscribers.count',
-    'subscribers.max',
-    'subscriptions.count',
-    'subscriptions.max',
-    'subscriptions.shared.count',
-    'subscriptions.shared.max'
-]).
+%% PubSub stats
+-define(PUBSUB_STATS,
+        ['topics.count',
+         'topics.max',
+         'suboptions.count',
+         'suboptions.max',
+         'subscribers.count',
+         'subscribers.max',
+         'subscriptions.count',
+         'subscriptions.max',
+         'subscriptions.shared.count',
+         'subscriptions.shared.max'
+        ]).
 
--define(ROUTE_STATS, [
-    'routes.count',
-    'routes.max'
-]).
+%% Route stats
+-define(ROUTE_STATS,
+        ['routes.count',
+         'routes.max'
+        ]).
 
 %% Retained stats
--define(RETAINED_STATS, [
-    'retained.count',
-    'retained.max'
-]).
+-define(RETAINED_STATS,
+        ['retained.count',
+         'retained.max'
+        ]).
 
 -define(TAB, ?MODULE).
 -define(SERVER, ?MODULE).
 
--type opts() :: #{tick_ms := timeout()}.
+-type(opts() :: #{tick_ms := timeout()}).
 
 %% @doc Start stats server
 -spec(start_link() -> startlink_ret()).
@@ -122,7 +127,7 @@ start_link(Opts) ->
 stop() ->
     gen_server:call(?SERVER, stop, infinity).
 
-%% @doc Generate stats fun
+%% @doc Generate stats fun.
 -spec(statsfun(Stat :: atom()) -> fun()).
 statsfun(Stat) ->
     fun(Val) -> setstat(Stat, Val) end.
@@ -131,7 +136,7 @@ statsfun(Stat) ->
 statsfun(Stat, MaxStat) ->
     fun(Val) -> setstat(Stat, MaxStat, Val) end.
 
-%% @doc Get all statistics
+%% @doc Get all statistics.
 -spec(getstats() -> stats()).
 getstats() ->
     case ets:info(?TAB, name) of
@@ -139,7 +144,7 @@ getstats() ->
         _ -> ets:tab2list(?TAB)
     end.
 
-%% @doc Get stats by name
+%% @doc Get stats by name.
 -spec(getstat(atom()) -> maybe(non_neg_integer())).
 getstat(Name) ->
     case ets:lookup(?TAB, Name) of
@@ -173,8 +178,7 @@ cancel_update(Name) ->
 rec(Name, Secs, UpFun) ->
     #update{name = Name, countdown = Secs, interval = Secs, func = UpFun}.
 
-cast(Msg) ->
-    gen_server:cast(?SERVER, Msg).
+cast(Msg) -> gen_server:cast(?SERVER, Msg).
 
 %%--------------------------------------------------------------------
 %% gen_server callbacks
@@ -182,8 +186,13 @@ cast(Msg) ->
 
 init(#{tick_ms := TickMs}) ->
     ok = emqx_tables:new(?TAB, [public, set, {write_concurrency, true}]),
-    Stats = lists:append([?CONNECTION_STATS, ?SESSION_STATS, ?PUBSUB_STATS,
-                          ?ROUTE_STATS, ?RETAINED_STATS]),
+    Stats = lists:append([?CONNECTION_STATS,
+                          ?CHANNEL_STATS,
+                          ?SESSION_STATS,
+                          ?PUBSUB_STATS,
+                          ?ROUTE_STATS,
+                          ?RETAINED_STATS
+                         ]),
     true = ets:insert(?TAB, [{Name, 0} || Name <- Stats]),
     {ok, start_timer(#state{updates = [], tick_ms = TickMs}), hibernate}.
 
@@ -211,16 +220,17 @@ handle_cast({setstat, Stat, MaxStat, Val}, State) ->
 
 handle_cast({update_interval, Update = #update{name = Name}},
             State = #state{updates = Updates}) ->
-    case lists:keyfind(Name, #update.name, Updates) of
-        #update{} ->
-            ?LOG(warning, "Duplicated update: ~s", [Name]),
-            {noreply, State};
-        false ->
-            {noreply, State#state{updates = [Update | Updates]}}
-    end;
+    NState = case lists:keyfind(Name, #update.name, Updates) of
+                 #update{} ->
+                     ?LOG(warning, "Duplicated update: ~s", [Name]),
+                     State;
+                 false -> State#state{updates = [Update|Updates]}
+             end,
+    {noreply, NState};
 
 handle_cast({cancel_update, Name}, State = #state{updates = Updates}) ->
-    {noreply, State#state{updates = lists:keydelete(Name, #update.name, Updates)}};
+    Updates1 = lists:keydelete(Name, #update.name, Updates),
+    {noreply, State#state{updates = Updates1}};
 
 handle_cast(Msg, State) ->
     ?LOG(error, "Unexpected cast: ~p", [Msg]),
@@ -233,7 +243,7 @@ handle_info({timeout, TRef, tick}, State = #state{timer = TRef, updates = Update
                          try UpFun()
                          catch
                              _:Error ->
-                                 ?LOG(error, "update ~s failed: ~p", [Name, Error])
+                                 ?LOG(error, "Update ~s failed: ~p", [Name, Error])
                          end,
                          [Update#update{countdown = I} | Acc];
                     (Update = #update{countdown = C}, Acc) ->
@@ -259,10 +269,9 @@ safe_update_element(Key, Val) ->
     try ets:update_element(?TAB, Key, {2, Val}) of
         false ->
             ets:insert_new(?TAB, {Key, Val});
-        true ->
-            true
+        true -> true
     catch
         error:badarg ->
-            ?LOG(warning, "Update ~p to ~p failed", [Key, Val])
+            ?LOG(warning, "Failed to update ~p to ~p", [Key, Val])
     end.