emqx4.3/apps/emqx/src/emqx_metrics.erl

%%--------------------------------------------------------------------
%% Copyright (c) 2017-2023 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_metrics).

-behaviour(gen_server).

-include("emqx.hrl").
-include("logger.hrl").
-include("types.hrl").
-include("emqx_mqtt.hrl").

-export([
    start_link/0,
    stop/0
]).

-export([
    new/1,
    new/2,
    ensure/1,
    ensure/2,
    all/0
]).

-export([
    val/1,
    inc/1,
    inc/2,
    dec/1,
    dec/2,
    set/2
]).

-export([
    trans/2,
    trans/3,
    commit/0
]).

%% Inc received/sent metrics
-export([
    inc_msg/1,
    inc_recv/1,
    inc_sent/1
]).

%% gen_server callbacks
-export([
    init/1,
    handle_call/3,
    handle_cast/2,
    handle_info/2,
    terminate/2,
    code_change/3
]).

%% BACKW: v4.3.0
-export([upgrade_retained_delayed_counter_type/0]).

-export_type([metric_idx/0]).

-compile({inline, [inc/1, inc/2, dec/1, dec/2]}).
-compile({inline, [inc_recv/1, inc_sent/1]}).

-opaque metric_idx() :: 1..1024.

-type metric_name() :: atom() | string() | binary().

-define(MAX_SIZE, 1024).
-define(RESERVED_IDX, 512).
-define(TAB, ?MODULE).
-define(SERVER, ?MODULE).

%% Bytes sent and received
-define(BYTES_METRICS,
    % Total bytes received
    [
        {counter, 'bytes.received'},
        % Total bytes sent
        {counter, 'bytes.sent'}
    ]
).

%% Packets sent and received
-define(PACKET_METRICS,
    % All Packets received
    [
        {counter, 'packets.received'},
        % All Packets sent
        {counter, 'packets.sent'},
        % CONNECT Packets received
        {counter, 'packets.connect.received'},
        % CONNACK Packets sent
        {counter, 'packets.connack.sent'},
        % CONNACK error sent
        {counter, 'packets.connack.error'},
        % CONNACK auth_error sent
        {counter, 'packets.connack.auth_error'},
        % PUBLISH packets received
        {counter, 'packets.publish.received'},
        % PUBLISH packets sent
        {counter, 'packets.publish.sent'},
        % PUBLISH packet_id inuse
        {counter, 'packets.publish.inuse'},
        % PUBLISH failed for error
        {counter, 'packets.publish.error'},
        % PUBLISH failed for auth error
        {counter, 'packets.publish.auth_error'},
        % PUBLISH(QoS2) packets dropped
        {counter, 'packets.publish.dropped'},
        % PUBACK packets received
        {counter, 'packets.puback.received'},
        % PUBACK packets sent
        {counter, 'packets.puback.sent'},
        % PUBACK packet_id inuse
        {counter, 'packets.puback.inuse'},
        % PUBACK packets missed
        {counter, 'packets.puback.missed'},
        % PUBREC packets received
        {counter, 'packets.pubrec.received'},
        % PUBREC packets sent
        {counter, 'packets.pubrec.sent'},
        % PUBREC packet_id inuse
        {counter, 'packets.pubrec.inuse'},
        % PUBREC packets missed
        {counter, 'packets.pubrec.missed'},
        % PUBREL packets received
        {counter, 'packets.pubrel.received'},
        % PUBREL packets sent
        {counter, 'packets.pubrel.sent'},
        % PUBREL packets missed
        {counter, 'packets.pubrel.missed'},
        % PUBCOMP packets received
        {counter, 'packets.pubcomp.received'},
        % PUBCOMP packets sent
        {counter, 'packets.pubcomp.sent'},
        % PUBCOMP packet_id inuse
        {counter, 'packets.pubcomp.inuse'},
        % PUBCOMP packets missed
        {counter, 'packets.pubcomp.missed'},
        % SUBSCRIBE Packets received
        {counter, 'packets.subscribe.received'},
        % SUBSCRIBE error
        {counter, 'packets.subscribe.error'},
        % SUBSCRIBE failed for not auth
        {counter, 'packets.subscribe.auth_error'},
        % SUBACK packets sent
        {counter, 'packets.suback.sent'},
        % UNSUBSCRIBE Packets received
        {counter, 'packets.unsubscribe.received'},
        % UNSUBSCRIBE error
        {counter, 'packets.unsubscribe.error'},
        % UNSUBACK Packets sent
        {counter, 'packets.unsuback.sent'},
        % PINGREQ packets received
        {counter, 'packets.pingreq.received'},
        % PINGRESP Packets sent
        {counter, 'packets.pingresp.sent'},
        % DISCONNECT Packets received
        {counter, 'packets.disconnect.received'},
        % DISCONNECT Packets sent
        {counter, 'packets.disconnect.sent'},
        % Auth Packets received
        {counter, 'packets.auth.received'},
        % Auth Packets sent
        {counter, 'packets.auth.sent'}
    ]
).

%% Messages sent/received and pubsub
-define(MESSAGE_METRICS,
    % All Messages received
    [
        {counter, 'messages.received'},
        % All Messages sent
        {counter, 'messages.sent'},
        % QoS0 Messages received
        {counter, 'messages.qos0.received'},
        % QoS0 Messages sent
        {counter, 'messages.qos0.sent'},
        % QoS1 Messages received
        {counter, 'messages.qos1.received'},
        % QoS1 Messages sent
        {counter, 'messages.qos1.sent'},
        % QoS2 Messages received
        {counter, 'messages.qos2.received'},
        % QoS2 Messages sent
        {counter, 'messages.qos2.sent'},
        %% PubSub Metrics

        % Messages Publish
        {counter, 'messages.publish'},
        % Messages dropped due to no subscribers
        {counter, 'messages.dropped'},
        % QoS2 Messages expired
        {counter, 'messages.dropped.await_pubrel_timeout'},
        % Messages dropped
        {counter, 'messages.dropped.no_subscribers'},
        % Messages forward
        {counter, 'messages.forward'},
        % Messages delayed
        {counter, 'messages.delayed'},
        % Messages delivered
        {counter, 'messages.delivered'},
        % Messages acked
        {counter, 'messages.acked'}
    ]
).

%% Delivery metrics
-define(DELIVERY_METRICS, [
    {counter, 'delivery.dropped'},
    {counter, 'delivery.dropped.no_local'},
    {counter, 'delivery.dropped.too_large'},
    {counter, 'delivery.dropped.qos0_msg'},
    {counter, 'delivery.dropped.queue_full'},
    {counter, 'delivery.dropped.expired'}
]).

%% Client Lifecircle metrics
-define(CLIENT_METRICS, [
    {counter, 'client.connect'},
    {counter, 'client.connack'},
    {counter, 'client.connected'},
    {counter, 'client.authenticate'},
    {counter, 'client.auth.anonymous'},
    {counter, 'client.authorize'},
    {counter, 'client.subscribe'},
    {counter, 'client.unsubscribe'},
    {counter, 'client.disconnected'}
]).

%% Session Lifecircle metrics
-define(SESSION_METRICS, [
    {counter, 'session.created'},
    {counter, 'session.resumed'},
    {counter, 'session.takenover'},
    {counter, 'session.discarded'},
    {counter, 'session.terminated'}
]).

%% Statistic metrics for ACL checking
-define(STASTS_ACL_METRICS, [
    {counter, 'authorization.allow'},
    {counter, 'authorization.deny'},
    {counter, 'authorization.cache_hit'}
]).

%% Statistic metrics for auth checking
-define(STASTS_AUTHN_METRICS, [
    {counter, 'authentication.success'},
    {counter, 'authentication.success.anonymous'},
    {counter, 'authentication.failure'}
]).

%% Overload protetion counters
-define(OLP_METRICS, [
    {counter, 'olp.delay.ok'},
    {counter, 'olp.delay.timeout'},
    {counter, 'olp.hbn'},
    {counter, 'olp.gc'},
    {counter, 'olp.new_conn'}
]).

-record(state, {next_idx = 1}).

-record(metric, {name, type, idx}).

%% @doc Start the metrics server.
-spec start_link() -> startlink_ret().
start_link() ->
    gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).

-spec stop() -> ok.
stop() ->
    try
        gen_server:stop(?SERVER)
    catch
        exit:R when R =:= noproc orelse R =:= timeout ->
            %% pid is killed after timeout
            ok
    end.

%% BACKW: v4.3.0
upgrade_retained_delayed_counter_type() ->
    Ks = ['messages.delayed'],
    gen_server:call(?SERVER, {set_type_to_counter, Ks}, infinity).

%%--------------------------------------------------------------------
%% Metrics API
%%--------------------------------------------------------------------

-spec new(metric_name()) -> ok.
new(Name) ->
    new(counter, Name).

-spec new(gauge | counter, metric_name()) -> ok.
new(gauge, Name) ->
    create(gauge, Name);
new(counter, Name) ->
    create(counter, Name).

-spec ensure(metric_name()) -> ok.
ensure(Name) ->
    ensure(counter, Name).

-spec ensure(gauge | counter, metric_name()) -> ok.
ensure(Type, Name) when Type =:= gauge; Type =:= counter ->
    case ets:lookup(?TAB, Name) of
        [] -> create(Type, Name);
        _ -> ok
    end.

%% @private
create(Type, Name) ->
    case gen_server:call(?SERVER, {create, Type, Name}) of
        {ok, _Idx} -> ok;
        {error, Reason} -> error(Reason)
    end.

%% @doc Get all metrics
-spec all() -> [{metric_name(), non_neg_integer()}].
all() ->
    CRef = persistent_term:get(?MODULE),
    [
        {Name, counters:get(CRef, Idx)}
     || #metric{name = Name, idx = Idx} <- ets:tab2list(?TAB)
    ].

%% @doc Get metric value
-spec val(metric_name()) -> non_neg_integer().
val(Name) ->
    try
        case ets:lookup(?TAB, Name) of
            [#metric{idx = Idx}] ->
                CRef = persistent_term:get(?MODULE),
                counters:get(CRef, Idx);
            [] ->
                0
        end
        %% application will restart when join cluster, then ets not exist.
    catch
        error:badarg ->
            0
    end.

%% @doc Increase counter
-spec inc(metric_name()) -> ok.
inc(Name) ->
    inc(Name, 1).

%% @doc Increase metric value
-spec inc(metric_name(), pos_integer()) -> ok.
inc(Name, Value) ->
    update_counter(Name, Value).

%% @doc Decrease metric value
-spec dec(metric_name()) -> ok.
dec(Name) ->
    dec(Name, 1).

%% @doc Decrease metric value
-spec dec(metric_name(), pos_integer()) -> ok.
dec(Name, Value) ->
    update_counter(Name, -Value).

%% @doc Set metric value
-spec set(metric_name(), integer()) -> ok.
set(Name, Value) ->
    CRef = persistent_term:get(?MODULE),
    Idx = ets:lookup_element(?TAB, Name, 4),
    counters:put(CRef, Idx, Value).

-spec trans(inc | dec, metric_name()) -> ok.
trans(Op, Name) when Op =:= inc; Op =:= dec ->
    trans(Op, Name, 1).

-spec trans(inc | dec, metric_name(), pos_integer()) -> ok.
trans(inc, Name, Value) ->
    cache(Name, Value);
trans(dec, Name, Value) ->
    cache(Name, -Value).

-spec cache(metric_name(), integer()) -> ok.
cache(Name, Value) ->
    put(
        '$metrics',
        case get('$metrics') of
            undefined ->
                #{Name => Value};
            Metrics ->
                maps:update_with(Name, fun(Cnt) -> Cnt + Value end, Value, Metrics)
        end
    ),
    ok.

-spec commit() -> ok.
commit() ->
    case get('$metrics') of
        undefined ->
            ok;
        Metrics ->
            _ = erase('$metrics'),
            lists:foreach(fun update_counter/1, maps:to_list(Metrics))
    end.

update_counter({Name, Value}) ->
    update_counter(Name, Value).

update_counter(Name, Value) ->
    CRef = persistent_term:get(?MODULE),
    CIdx =
        case reserved_idx(Name) of
            Idx when is_integer(Idx) -> Idx;
            undefined -> ets:lookup_element(?TAB, Name, 4)
        end,
    counters:add(CRef, CIdx, Value).

%%--------------------------------------------------------------------
%% Inc received/sent metrics
%%--------------------------------------------------------------------

-spec inc_msg(emqx_types:massage()) -> ok.
inc_msg(Msg) ->
    case Msg#message.qos of
        0 -> inc('messages.qos0.received');
        1 -> inc('messages.qos1.received');
        2 -> inc('messages.qos2.received')
    end,
    inc('messages.received').

%% @doc Inc packets received.
-spec inc_recv(emqx_types:packet()) -> ok.
inc_recv(Packet) ->
    inc('packets.received'),
    do_inc_recv(Packet).

do_inc_recv(?PACKET(?CONNECT)) ->
    inc('packets.connect.received');
do_inc_recv(?PUBLISH_PACKET(QoS)) ->
    inc('messages.received'),
    case QoS of
        ?QOS_0 -> inc('messages.qos0.received');
        ?QOS_1 -> inc('messages.qos1.received');
        ?QOS_2 -> inc('messages.qos2.received');
        _other -> ok
    end,
    inc('packets.publish.received');
do_inc_recv(?PACKET(?PUBACK)) ->
    inc('packets.puback.received');
do_inc_recv(?PACKET(?PUBREC)) ->
    inc('packets.pubrec.received');
do_inc_recv(?PACKET(?PUBREL)) ->
    inc('packets.pubrel.received');
do_inc_recv(?PACKET(?PUBCOMP)) ->
    inc('packets.pubcomp.received');
do_inc_recv(?PACKET(?SUBSCRIBE)) ->
    inc('packets.subscribe.received');
do_inc_recv(?PACKET(?UNSUBSCRIBE)) ->
    inc('packets.unsubscribe.received');
do_inc_recv(?PACKET(?PINGREQ)) ->
    inc('packets.pingreq.received');
do_inc_recv(?PACKET(?DISCONNECT)) ->
    inc('packets.disconnect.received');
do_inc_recv(?PACKET(?AUTH)) ->
    inc('packets.auth.received');
do_inc_recv(_Packet) ->
    ok.

%% @doc Inc packets sent. Will not count $SYS PUBLISH.
-spec inc_sent(emqx_types:packet()) -> ok.
inc_sent(?PUBLISH_PACKET(_QoS, <<"$SYS/", _/binary>>, _, _)) ->
    ok;
inc_sent(Packet) ->
    inc('packets.sent'),
    do_inc_sent(Packet).

do_inc_sent(?CONNACK_PACKET(ReasonCode)) ->
    (ReasonCode == ?RC_SUCCESS) orelse inc('packets.connack.error'),
    ((ReasonCode == ?RC_NOT_AUTHORIZED) orelse
        (ReasonCode == ?CONNACK_AUTH)) andalso
        inc('packets.connack.auth_error'),
    ((ReasonCode == ?RC_BAD_USER_NAME_OR_PASSWORD) orelse
        (ReasonCode == ?CONNACK_CREDENTIALS)) andalso
        inc('packets.connack.auth_error'),
    inc('packets.connack.sent');
do_inc_sent(?PUBLISH_PACKET(QoS)) ->
    inc('messages.sent'),
    case QoS of
        ?QOS_0 -> inc('messages.qos0.sent');
        ?QOS_1 -> inc('messages.qos1.sent');
        ?QOS_2 -> inc('messages.qos2.sent');
        _other -> ok
    end,
    inc('packets.publish.sent');
do_inc_sent(?PUBACK_PACKET(_PacketId, ReasonCode)) ->
    (ReasonCode >= ?RC_UNSPECIFIED_ERROR) andalso inc('packets.publish.error'),
    (ReasonCode == ?RC_NOT_AUTHORIZED) andalso inc('packets.publish.auth_error'),
    inc('packets.puback.sent');
do_inc_sent(?PUBREC_PACKET(_PacketId, ReasonCode)) ->
    (ReasonCode >= ?RC_UNSPECIFIED_ERROR) andalso inc('packets.publish.error'),
    (ReasonCode == ?RC_NOT_AUTHORIZED) andalso inc('packets.publish.auth_error'),
    inc('packets.pubrec.sent');
do_inc_sent(?PACKET(?PUBREL)) ->
    inc('packets.pubrel.sent');
do_inc_sent(?PACKET(?PUBCOMP)) ->
    inc('packets.pubcomp.sent');
do_inc_sent(?PACKET(?SUBACK)) ->
    inc('packets.suback.sent');
do_inc_sent(?PACKET(?UNSUBACK)) ->
    inc('packets.unsuback.sent');
do_inc_sent(?PACKET(?PINGRESP)) ->
    inc('packets.pingresp.sent');
do_inc_sent(?PACKET(?DISCONNECT)) ->
    inc('packets.disconnect.sent');
do_inc_sent(?PACKET(?AUTH)) ->
    inc('packets.auth.sent');
do_inc_sent(_Packet) ->
    ok.

%%--------------------------------------------------------------------
%% gen_server callbacks
%%--------------------------------------------------------------------

init([]) ->
    % Create counters array
    CRef = counters:new(?MAX_SIZE, [write_concurrency]),
    ok = persistent_term:put(?MODULE, CRef),
    % Create index mapping table
    ok = emqx_utils_ets:new(?TAB, [{keypos, 2}, {read_concurrency, true}]),
    Metrics = lists:append([
        ?BYTES_METRICS,
        ?PACKET_METRICS,
        ?MESSAGE_METRICS,
        ?DELIVERY_METRICS,
        ?CLIENT_METRICS,
        ?SESSION_METRICS,
        ?STASTS_ACL_METRICS,
        ?STASTS_AUTHN_METRICS,
        ?OLP_METRICS
    ]),
    % Store reserved indices
    ok = lists:foreach(
        fun({Type, Name}) ->
            Idx = reserved_idx(Name),
            Metric = #metric{name = Name, type = Type, idx = Idx},
            true = ets:insert(?TAB, Metric),
            ok = counters:put(CRef, Idx, 0)
        end,
        Metrics
    ),
    {ok, #state{next_idx = ?RESERVED_IDX + 1}, hibernate}.

handle_call({create, Type, Name}, _From, State = #state{next_idx = ?MAX_SIZE}) ->
    ?SLOG(error, #{
        msg => "failed_to_create_type_name_for_index_exceeded",
        type => Type,
        name => Name
    }),
    {reply, {error, metric_index_exceeded}, State};
handle_call({create, Type, Name}, _From, State = #state{next_idx = NextIdx}) ->
    case ets:lookup(?TAB, Name) of
        [#metric{idx = Idx}] ->
            ?SLOG(info, #{msg => "name_already_exists", name => Name}),
            {reply, {ok, Idx}, State};
        [] ->
            Metric = #metric{name = Name, type = Type, idx = NextIdx},
            true = ets:insert(?TAB, Metric),
            {reply, {ok, NextIdx}, State#state{next_idx = NextIdx + 1}}
    end;
handle_call({set_type_to_counter, Keys}, _From, State) ->
    lists:foreach(
        fun(K) ->
            ets:update_element(?TAB, K, {#metric.type, counter})
        end,
        Keys
    ),
    {reply, ok, State};
handle_call(Req, _From, State) ->
    ?SLOG(error, #{msg => "unexpected_call", req => Req}),
    {reply, ignored, State}.

handle_cast(Msg, State) ->
    ?SLOG(error, #{msg => "unexpected_cast", req => Msg}),
    {noreply, State}.

handle_info(Info, State) ->
    ?SLOG(error, #{msg => "unexpected_info", info => Info}),
    {noreply, State}.

terminate(_Reason, _State) ->
    ok.

code_change(_OldVsn, State, _Extra) ->
    {ok, State}.

%%--------------------------------------------------------------------
%% Internal functions
%%--------------------------------------------------------------------

reserved_idx('bytes.received') -> 01;
reserved_idx('bytes.sent') -> 02;
%% Reserved indices of packet's metrics
reserved_idx('packets.received') -> 10;
reserved_idx('packets.sent') -> 11;
reserved_idx('packets.connect.received') -> 12;
reserved_idx('packets.connack.sent') -> 13;
reserved_idx('packets.connack.error') -> 14;
reserved_idx('packets.connack.auth_error') -> 15;
reserved_idx('packets.publish.received') -> 16;
reserved_idx('packets.publish.sent') -> 17;
reserved_idx('packets.publish.inuse') -> 18;
reserved_idx('packets.publish.error') -> 19;
reserved_idx('packets.publish.auth_error') -> 20;
reserved_idx('packets.puback.received') -> 21;
reserved_idx('packets.puback.sent') -> 22;
reserved_idx('packets.puback.inuse') -> 23;
reserved_idx('packets.puback.missed') -> 24;
reserved_idx('packets.pubrec.received') -> 25;
reserved_idx('packets.pubrec.sent') -> 26;
reserved_idx('packets.pubrec.inuse') -> 27;
reserved_idx('packets.pubrec.missed') -> 28;
reserved_idx('packets.pubrel.received') -> 29;
reserved_idx('packets.pubrel.sent') -> 30;
reserved_idx('packets.pubrel.missed') -> 31;
reserved_idx('packets.pubcomp.received') -> 32;
reserved_idx('packets.pubcomp.sent') -> 33;
reserved_idx('packets.pubcomp.inuse') -> 34;
reserved_idx('packets.pubcomp.missed') -> 35;
reserved_idx('packets.subscribe.received') -> 36;
reserved_idx('packets.subscribe.error') -> 37;
reserved_idx('packets.subscribe.auth_error') -> 38;
reserved_idx('packets.suback.sent') -> 39;
reserved_idx('packets.unsubscribe.received') -> 40;
reserved_idx('packets.unsubscribe.error') -> 41;
reserved_idx('packets.unsuback.sent') -> 42;
reserved_idx('packets.pingreq.received') -> 43;
reserved_idx('packets.pingresp.sent') -> 44;
reserved_idx('packets.disconnect.received') -> 45;
reserved_idx('packets.disconnect.sent') -> 46;
reserved_idx('packets.auth.received') -> 47;
reserved_idx('packets.auth.sent') -> 48;
reserved_idx('packets.publish.dropped') -> 49;
%% Reserved indices of message's metrics
reserved_idx('messages.received') -> 100;
reserved_idx('messages.sent') -> 101;
reserved_idx('messages.qos0.received') -> 102;
reserved_idx('messages.qos0.sent') -> 103;
reserved_idx('messages.qos1.received') -> 104;
reserved_idx('messages.qos1.sent') -> 105;
reserved_idx('messages.qos2.received') -> 106;
reserved_idx('messages.qos2.sent') -> 107;
reserved_idx('messages.publish') -> 108;
reserved_idx('messages.dropped') -> 109;
reserved_idx('messages.dropped.await_pubrel_timeout') -> 110;
reserved_idx('messages.dropped.no_subscribers') -> 111;
reserved_idx('messages.forward') -> 112;
%%reserved_idx('messages.retained')            -> 113; %% keep the index, new metrics can use this
reserved_idx('messages.delayed') -> 114;
reserved_idx('messages.delivered') -> 115;
reserved_idx('messages.acked') -> 116;
reserved_idx('delivery.expired') -> 117;
reserved_idx('delivery.dropped') -> 118;
reserved_idx('delivery.dropped.no_local') -> 119;
reserved_idx('delivery.dropped.too_large') -> 120;
reserved_idx('delivery.dropped.qos0_msg') -> 121;
reserved_idx('delivery.dropped.queue_full') -> 122;
reserved_idx('delivery.dropped.expired') -> 123;
reserved_idx('client.connect') -> 200;
reserved_idx('client.connack') -> 201;
reserved_idx('client.connected') -> 202;
reserved_idx('client.authenticate') -> 203;
reserved_idx('client.enhanced_authenticate') -> 204;
reserved_idx('client.auth.anonymous') -> 205;
reserved_idx('client.authorize') -> 206;
reserved_idx('client.subscribe') -> 207;
reserved_idx('client.unsubscribe') -> 208;
reserved_idx('client.disconnected') -> 209;
reserved_idx('session.created') -> 220;
reserved_idx('session.resumed') -> 221;
reserved_idx('session.takenover') -> 222;
reserved_idx('session.discarded') -> 223;
reserved_idx('session.terminated') -> 224;
reserved_idx('authorization.allow') -> 300;
reserved_idx('authorization.deny') -> 301;
reserved_idx('authorization.cache_hit') -> 302;
reserved_idx('authentication.success') -> 310;
reserved_idx('authentication.success.anonymous') -> 311;
reserved_idx('authentication.failure') -> 312;
reserved_idx('olp.delay.ok') -> 400;
reserved_idx('olp.delay.timeout') -> 401;
reserved_idx('olp.hbn') -> 402;
reserved_idx('olp.gc') -> 403;
reserved_idx('olp.new_conn') -> 404;
reserved_idx(_) -> undefined.