dgiot/src/emqx_stats.erl
2021-05-18 14:54:48 +08:00

278 lines
8.1 KiB
Erlang

%%--------------------------------------------------------------------
%% Copyright (c) 2017-2021 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_stats).
-behaviour(gen_server).
-include("emqx.hrl").
-include("logger.hrl").
-include("types.hrl").
-logger_header("[Stats]").
%% APIs
-export([ start_link/0
, start_link/1
, stop/0
]).
%% Stats API.
-export([ getstats/0
, getstat/1
, setstat/2
, setstat/3
, statsfun/1
, statsfun/2
]).
-export([ update_interval/2
, update_interval/3
, cancel_update/1
]).
%% gen_server callbacks
-export([ init/1
, handle_call/3
, handle_cast/2
, handle_info/2
, terminate/2
, code_change/3
]).
-export_type([stats/0]).
-record(update, {name, countdown, interval, func}).
-record(state, {
timer :: maybe(reference()),
updates :: [#update{}],
tick_ms :: timeout()
}).
-type(stats() :: list({atom(), non_neg_integer()})).
%% Connection stats
-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', %% Count of Concurrent Sessions
'sessions.max' %% Maximum Number of Concurrent Sessions
]).
%% 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'
]).
%% Route stats
-define(ROUTE_STATS,
['routes.count',
'routes.max'
]).
%% Retained stats
-define(RETAINED_STATS,
['retained.count',
'retained.max'
]).
-define(TAB, ?MODULE).
-define(SERVER, ?MODULE).
-type(opts() :: #{tick_ms := timeout()}).
%% @doc Start stats server
-spec(start_link() -> startlink_ret()).
start_link() ->
start_link(#{tick_ms => timer:seconds(1)}).
-spec(start_link(opts()) -> startlink_ret()).
start_link(Opts) ->
gen_server:start_link({local, ?SERVER}, ?MODULE, Opts, []).
-spec(stop() -> ok).
stop() ->
gen_server:call(?SERVER, stop, infinity).
%% @doc Generate stats fun.
-spec(statsfun(Stat :: atom()) -> fun()).
statsfun(Stat) ->
fun(Val) -> setstat(Stat, Val) end.
-spec(statsfun(Stat :: atom(), MaxStat :: atom()) -> fun()).
statsfun(Stat, MaxStat) ->
fun(Val) -> setstat(Stat, MaxStat, Val) end.
%% @doc Get all statistics.
-spec(getstats() -> stats()).
getstats() ->
case ets:info(?TAB, name) of
undefined -> [];
_ -> ets:tab2list(?TAB)
end.
%% @doc Get stats by name.
-spec(getstat(atom()) -> maybe(non_neg_integer())).
getstat(Name) ->
case ets:lookup(?TAB, Name) of
[{Name, Val}] -> Val;
[] -> undefined
end.
%% @doc Set stats
-spec(setstat(Stat :: atom(), Val :: pos_integer()) -> boolean()).
setstat(Stat, Val) when is_integer(Val) ->
safe_update_element(Stat, Val).
%% @doc Set stats with max value.
-spec(setstat(Stat :: atom(), MaxStat :: atom(),
Val :: pos_integer()) -> ok).
setstat(Stat, MaxStat, Val) when is_integer(Val) ->
cast({setstat, Stat, MaxStat, Val}).
-spec(update_interval(atom(), fun()) -> ok).
update_interval(Name, UpFun) ->
update_interval(Name, 1, UpFun).
-spec(update_interval(atom(), pos_integer(), fun()) -> ok).
update_interval(Name, Secs, UpFun) when is_integer(Secs), Secs >= 1 ->
cast({update_interval, rec(Name, Secs, UpFun)}).
-spec(cancel_update(atom()) -> ok).
cancel_update(Name) ->
cast({cancel_update, Name}).
rec(Name, Secs, UpFun) ->
#update{name = Name, countdown = Secs, interval = Secs, func = UpFun}.
cast(Msg) -> gen_server:cast(?SERVER, Msg).
%%--------------------------------------------------------------------
%% gen_server callbacks
%%--------------------------------------------------------------------
init(#{tick_ms := TickMs}) ->
ok = emqx_tables:new(?TAB, [public, set, {write_concurrency, true}]),
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}.
start_timer(#state{tick_ms = Ms} = State) ->
State#state{timer = emqx_misc:start_timer(Ms, tick)}.
handle_call(stop, _From, State) ->
{stop, normal, ok, State};
handle_call(Req, _From, State) ->
?LOG(error, "Unexpected call: ~p", [Req]),
{reply, ignored, State}.
handle_cast({setstat, Stat, MaxStat, Val}, State) ->
try ets:lookup_element(?TAB, MaxStat, 2) of
MaxVal when Val > MaxVal ->
ets:update_element(?TAB, MaxStat, {2, Val});
_ -> ok
catch
error:badarg ->
ets:insert(?TAB, {MaxStat, Val})
end,
safe_update_element(Stat, Val),
{noreply, State};
handle_cast({update_interval, Update = #update{name = Name}},
State = #state{updates = Updates}) ->
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}) ->
Updates1 = lists:keydelete(Name, #update.name, Updates),
{noreply, State#state{updates = Updates1}};
handle_cast(Msg, State) ->
?LOG(error, "Unexpected cast: ~p", [Msg]),
{noreply, State}.
handle_info({timeout, TRef, tick}, State = #state{timer = TRef, updates = Updates}) ->
Updates1 = lists:foldl(
fun(Update = #update{name = Name, countdown = C, interval = I,
func = UpFun}, Acc) when C =< 0 ->
try UpFun()
catch
_:Error ->
?LOG(error, "Update ~s failed: ~0p", [Name, Error])
end,
[Update#update{countdown = I} | Acc];
(Update = #update{countdown = C}, Acc) ->
[Update#update{countdown = C - 1} | Acc]
end, [], Updates),
{noreply, start_timer(State#state{updates = Updates1}), hibernate};
handle_info(Info, State) ->
?LOG(error, "Unexpected info: ~p", [Info]),
{noreply, State}.
terminate(_Reason, #state{timer = TRef}) ->
emqx_misc:cancel_timer(TRef).
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%--------------------------------------------------------------------
%% Internal functions
%%--------------------------------------------------------------------
safe_update_element(Key, Val) ->
try ets:update_element(?TAB, Key, {2, Val}) of
false ->
ets:insert_new(?TAB, {Key, Val});
true -> true
catch
error:badarg ->
?LOG(warning, "Failed to update ~0p to ~0p", [Key, Val])
end.