Files
fx-test/fluxer_gateway/src/telemetry/gateway_metrics_collector.erl
2026-03-13 09:47:47 +01:00

412 lines
15 KiB
Erlang

%% Copyright (C) 2026 Fluxer Contributors
%%
%% This file is part of Fluxer.
%%
%% Fluxer is free software: you can redistribute it and/or modify
%% it under the terms of the GNU Affero General Public License as published by
%% the Free Software Foundation, either version 3 of the License, or
%% (at your option) any later version.
%%
%% Fluxer is distributed in the hope that it will be useful,
%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
%% GNU Affero General Public License for more details.
%%
%% You should have received a copy of the GNU Affero General Public License
%% along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
-module(gateway_metrics_collector).
-behaviour(gen_server).
-export([start_link/0]).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
-export([
inc_connections/0,
inc_disconnections/0,
inc_heartbeat_success/0,
inc_heartbeat_failure/0,
inc_resume_success/0,
inc_resume_failure/0,
inc_identify_rate_limited/0,
record_rpc_latency/1,
inc_websocket_close/1
]).
-type state() :: #{
report_interval_ms := pos_integer(),
timer_ref := reference() | undefined,
connections := non_neg_integer(),
disconnections := non_neg_integer(),
heartbeat_success := non_neg_integer(),
heartbeat_failure := non_neg_integer(),
resume_success := non_neg_integer(),
resume_failure := non_neg_integer(),
identify_rate_limited := non_neg_integer(),
rpc_latencies := [non_neg_integer()]
}.
-define(DEFAULT_REPORT_INTERVAL_MS, 30000).
-spec start_link() -> {ok, pid()} | {error, term()}.
start_link() ->
gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
-spec init(list()) -> {ok, state()}.
init([]) ->
Enabled = get_enabled(),
ReportInterval = get_report_interval(),
BaseState = #{
report_interval_ms => ReportInterval,
timer_ref => undefined,
connections => 0,
disconnections => 0,
heartbeat_success => 0,
heartbeat_failure => 0,
resume_success => 0,
resume_failure => 0,
identify_rate_limited => 0,
rpc_latencies => []
},
case Enabled of
true ->
logger:info("[gateway_metrics_collector] starting with ~p ms interval", [ReportInterval]),
TimerRef = schedule_collection(ReportInterval),
{ok, BaseState#{timer_ref := TimerRef}};
false ->
logger:info("[gateway_metrics_collector] disabled"),
{ok, BaseState}
end.
-spec handle_call(term(), gen_server:from(), state()) -> {reply, term(), state()}.
handle_call(_Request, _From, State) ->
{reply, ok, State}.
-spec handle_cast(term(), state()) -> {noreply, state()}.
handle_cast(inc_connections, #{connections := Connections} = State) ->
{noreply, State#{connections := Connections + 1}};
handle_cast(inc_disconnections, #{disconnections := Disconnections} = State) ->
{noreply, State#{disconnections := Disconnections + 1}};
handle_cast(inc_heartbeat_success, #{heartbeat_success := HeartbeatSuccess} = State) ->
{noreply, State#{heartbeat_success := HeartbeatSuccess + 1}};
handle_cast(inc_heartbeat_failure, #{heartbeat_failure := HeartbeatFailure} = State) ->
{noreply, State#{heartbeat_failure := HeartbeatFailure + 1}};
handle_cast(inc_resume_success, #{resume_success := ResumeSuccess} = State) ->
{noreply, State#{resume_success := ResumeSuccess + 1}};
handle_cast(inc_resume_failure, #{resume_failure := ResumeFailure} = State) ->
{noreply, State#{resume_failure := ResumeFailure + 1}};
handle_cast(inc_identify_rate_limited, #{identify_rate_limited := IdentifyRateLimited} = State) ->
{noreply, State#{identify_rate_limited := IdentifyRateLimited + 1}};
handle_cast({record_rpc_latency, LatencyMs}, #{rpc_latencies := Latencies} = State) ->
MaxLatencies = 1000,
NewLatencies = case length(Latencies) >= MaxLatencies of
true -> [LatencyMs | lists:sublist(Latencies, MaxLatencies - 1)];
false -> [LatencyMs | Latencies]
end,
{noreply, State#{rpc_latencies := NewLatencies}};
handle_cast(_Msg, State) ->
{noreply, State}.
-spec handle_info(term(), state()) -> {noreply, state()}.
handle_info(collect_and_report, #{report_interval_ms := Interval} = State) ->
collect_and_report_metrics(State),
TimerRef = schedule_collection(Interval),
ResetState = State#{
timer_ref := TimerRef,
connections := 0,
disconnections := 0,
heartbeat_success := 0,
heartbeat_failure := 0,
resume_success := 0,
resume_failure := 0,
identify_rate_limited := 0,
rpc_latencies := []
},
{noreply, ResetState};
handle_info(_Info, State) ->
{noreply, State}.
-spec terminate(term(), state()) -> ok.
terminate(_Reason, #{timer_ref := TimerRef}) ->
case TimerRef of
undefined -> ok;
Ref -> erlang:cancel_timer(Ref)
end,
ok.
-spec code_change(term(), state() | tuple(), term()) -> {ok, state()}.
code_change(_OldVsn, {state, ReportIntervalMs, TimerRef, Connections, Disconnections,
HeartbeatSuccess, HeartbeatFailure, ResumeSuccess, ResumeFailure,
IdentifyRateLimited, RpcLatencies}, _Extra) ->
{ok, #{
report_interval_ms => ReportIntervalMs,
timer_ref => TimerRef,
connections => Connections,
disconnections => Disconnections,
heartbeat_success => HeartbeatSuccess,
heartbeat_failure => HeartbeatFailure,
resume_success => ResumeSuccess,
resume_failure => ResumeFailure,
identify_rate_limited => IdentifyRateLimited,
rpc_latencies => RpcLatencies
}};
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
-spec schedule_collection(pos_integer()) -> reference().
schedule_collection(IntervalMs) ->
erlang:send_after(IntervalMs, self(), collect_and_report).
-spec get_enabled() -> boolean().
get_enabled() ->
case fluxer_gateway_env:get(gateway_metrics_enabled) of
false -> false;
_ -> metrics_client:is_enabled()
end.
-spec get_report_interval() -> pos_integer().
get_report_interval() ->
case fluxer_gateway_env:get(gateway_metrics_report_interval_ms) of
Value when is_integer(Value), Value > 0 -> Value;
_ -> ?DEFAULT_REPORT_INTERVAL_MS
end.
-spec collect_and_report_metrics(state()) -> ok.
collect_and_report_metrics(State) ->
Gauges = lists:flatten([
collect_process_counts(),
collect_mailbox_sizes(),
collect_memory_stats(),
collect_system_stats(),
collect_event_metrics(State)
]),
case Gauges of
[] -> ok;
_ -> metrics_client:batch(Gauges)
end.
-spec collect_event_metrics(state()) -> [map()].
collect_event_metrics(State) ->
#{
rpc_latencies := RpcLatencies,
connections := Connections,
disconnections := Disconnections,
heartbeat_success := HeartbeatSuccess,
heartbeat_failure := HeartbeatFailure,
resume_success := ResumeSuccess,
resume_failure := ResumeFailure,
identify_rate_limited := IdentifyRateLimited
} = State,
RpcLatencyStats = calculate_latency_stats(RpcLatencies),
lists:flatten([
[gauge(<<"gateway.websocket.connections">>, Connections)],
[gauge(<<"gateway.websocket.disconnections">>, Disconnections)],
[gauge(<<"gateway.heartbeat.success">>, HeartbeatSuccess)],
[gauge(<<"gateway.heartbeat.failure">>, HeartbeatFailure)],
[gauge(<<"gateway.resume.success">>, ResumeSuccess)],
[gauge(<<"gateway.resume.failure">>, ResumeFailure)],
[gauge(<<"gateway.identify.rate_limited">>, IdentifyRateLimited)],
RpcLatencyStats
]).
-spec calculate_latency_stats([non_neg_integer()]) -> [map()].
calculate_latency_stats([]) ->
[];
calculate_latency_stats(Latencies) ->
Sorted = lists:sort(Latencies),
Count = length(Sorted),
Sum = lists:sum(Sorted),
Avg = Sum / Count,
Min = hd(Sorted),
Max = lists:last(Sorted),
P50 = percentile(Sorted, 50),
P95 = percentile(Sorted, 95),
P99 = percentile(Sorted, 99),
[
gauge(<<"gateway.rpc.latency.avg">>, Avg),
gauge(<<"gateway.rpc.latency.min">>, Min),
gauge(<<"gateway.rpc.latency.max">>, Max),
gauge(<<"gateway.rpc.latency.p50">>, P50),
gauge(<<"gateway.rpc.latency.p95">>, P95),
gauge(<<"gateway.rpc.latency.p99">>, P99),
gauge(<<"gateway.rpc.latency.count">>, Count)
].
-spec percentile([number()], number()) -> number().
percentile(SortedList, Percent) ->
Len = length(SortedList),
Index = max(1, min(Len, round(Len * Percent / 100))),
lists:nth(Index, SortedList).
-spec collect_process_counts() -> [map()].
collect_process_counts() ->
SessionCount = get_manager_count(session_manager),
GuildCount = get_manager_count(guild_manager),
PresenceCount = get_manager_count(presence_manager),
CallCount = get_manager_count(call_manager),
[
gauge(<<"gateway.sessions.count">>, SessionCount),
gauge(<<"gateway.guilds.count">>, GuildCount),
gauge(<<"gateway.presences.count">>, PresenceCount),
gauge(<<"gateway.calls.count">>, CallCount)
].
-spec get_manager_count(atom()) -> non_neg_integer().
get_manager_count(Manager) ->
case catch gen_server:call(Manager, get_global_count, 1000) of
{ok, Count} when is_integer(Count) -> Count;
Count when is_integer(Count) -> Count;
_ -> 0
end.
-spec collect_mailbox_sizes() -> [map()].
collect_mailbox_sizes() ->
Managers = [
{session_manager, <<"gateway.mailbox.session_manager">>},
{guild_manager, <<"gateway.mailbox.guild_manager">>},
{presence_manager, <<"gateway.mailbox.presence_manager">>},
{call_manager, <<"gateway.mailbox.call_manager">>},
{push, <<"gateway.mailbox.push">>},
{presence_cache, <<"gateway.mailbox.presence_cache">>},
{presence_bus, <<"gateway.mailbox.presence_bus">>}
],
MailboxMetrics = lists:filtermap(fun({Manager, MetricName}) ->
case get_mailbox_size(Manager) of
undefined -> false;
Size -> {true, gauge(MetricName, Size)}
end
end, Managers),
TotalMailbox = lists:foldl(fun({Manager, _}, Acc) ->
case get_mailbox_size(Manager) of
undefined -> Acc;
Size -> Acc + Size
end
end, 0, Managers),
[gauge(<<"gateway.mailbox.total">>, TotalMailbox) | MailboxMetrics].
-spec get_mailbox_size(atom()) -> non_neg_integer() | undefined.
get_mailbox_size(Manager) ->
case whereis(Manager) of
undefined -> undefined;
Pid ->
case erlang:process_info(Pid, message_queue_len) of
{message_queue_len, Size} -> Size;
undefined -> undefined
end
end.
-spec collect_memory_stats() -> [map()].
collect_memory_stats() ->
PresenceCacheMemory = get_presence_cache_memory(),
PushMemory = get_push_process_memory(),
GuildMemoryStats = collect_guild_memory_stats(),
lists:flatten([
[gauge(<<"gateway.memory.presence_cache">>, PresenceCacheMemory)],
[gauge(<<"gateway.memory.push">>, PushMemory)],
GuildMemoryStats
]).
-spec collect_guild_memory_stats() -> [map()].
collect_guild_memory_stats() ->
case catch process_memory_stats:get_guild_memory_stats(10000) of
GuildStats when is_list(GuildStats), length(GuildStats) > 0 ->
Memories = [maps:get(memory, G, 0) || G <- GuildStats],
TotalMemory = lists:sum(Memories),
GuildCount = length(Memories),
AvgMemory = TotalMemory / GuildCount,
MaxMemory = lists:max(Memories),
MinMemory = lists:min(Memories),
[
gauge(<<"gateway.memory.guilds.total">>, TotalMemory),
gauge(<<"gateway.memory.guilds.count">>, GuildCount),
gauge(<<"gateway.memory.guilds.avg">>, AvgMemory),
gauge(<<"gateway.memory.guilds.max">>, MaxMemory),
gauge(<<"gateway.memory.guilds.min">>, MinMemory)
];
_ ->
[]
end.
-spec get_presence_cache_memory() -> non_neg_integer().
get_presence_cache_memory() ->
case catch presence_cache:get_memory_stats() of
{ok, #{memory_bytes := Bytes}} -> Bytes;
_ -> 0
end.
-spec get_push_process_memory() -> non_neg_integer().
get_push_process_memory() ->
case whereis(push) of
undefined -> 0;
Pid ->
case erlang:process_info(Pid, memory) of
{memory, Bytes} -> Bytes;
undefined -> 0
end
end.
-spec collect_system_stats() -> [map()].
collect_system_stats() ->
{TotalMemory, ProcessMemory, SystemMemory} = get_memory_info(),
ProcessCount = erlang:system_info(process_count),
[
gauge(<<"gateway.memory.total">>, TotalMemory),
gauge(<<"gateway.memory.processes">>, ProcessMemory),
gauge(<<"gateway.memory.system">>, SystemMemory),
gauge(<<"gateway.process_count">>, ProcessCount)
].
-spec get_memory_info() -> {non_neg_integer(), non_neg_integer(), non_neg_integer()}.
get_memory_info() ->
MemData = erlang:memory(),
Total = proplists:get_value(total, MemData, 0),
Processes = proplists:get_value(processes, MemData, 0),
System = proplists:get_value(system, MemData, 0),
{Total, Processes, System}.
-spec gauge(binary(), number()) -> map().
gauge(Name, Value) ->
#{
type => gauge,
name => Name,
dimensions => #{},
value => Value
}.
-spec inc_connections() -> ok.
inc_connections() ->
gen_server:cast(?MODULE, inc_connections).
-spec inc_disconnections() -> ok.
inc_disconnections() ->
gen_server:cast(?MODULE, inc_disconnections).
-spec inc_heartbeat_success() -> ok.
inc_heartbeat_success() ->
gen_server:cast(?MODULE, inc_heartbeat_success).
-spec inc_heartbeat_failure() -> ok.
inc_heartbeat_failure() ->
gen_server:cast(?MODULE, inc_heartbeat_failure).
-spec inc_resume_success() -> ok.
inc_resume_success() ->
gen_server:cast(?MODULE, inc_resume_success).
-spec inc_resume_failure() -> ok.
inc_resume_failure() ->
gen_server:cast(?MODULE, inc_resume_failure).
-spec inc_identify_rate_limited() -> ok.
inc_identify_rate_limited() ->
gen_server:cast(?MODULE, inc_identify_rate_limited).
-spec record_rpc_latency(non_neg_integer()) -> ok.
record_rpc_latency(LatencyMs) ->
gen_server:cast(?MODULE, {record_rpc_latency, LatencyMs}).
-spec inc_websocket_close(atom()) -> ok.
inc_websocket_close(Reason) ->
ReasonBin = atom_to_binary(Reason, utf8),
metrics_client:counter(<<"gateway.websocket.close">>, #{<<"reason">> => ReasonBin}).