fix: disable log throttling if primary log level is debug

apps/emqx/include/logger.hrl

@@ -47,7 +47,7 @@
 ).
 
 -define(SLOG_THROTTLE(Level, Data, Meta),
-    case emqx_log_throttler:allow(Level, maps:get(msg, Data)) of
+    case emqx_log_throttler:allow(maps:get(msg, Data)) of
         true ->
             ?SLOG(Level, Data, Meta);
         false ->

apps/emqx/src/emqx_log_throttler.erl

@@ -25,7 +25,7 @@
 -export([start_link/0]).
 
 %% throttler API
--export([allow/2]).
+-export([allow/1]).
 
 %% gen_server callbacks
 -export([
@@ -50,23 +50,13 @@
 -define(MSGS_LIST, emqx:get_config([log, throttling, msgs], [])).
 -define(TIME_WINDOW_MS, timer:seconds(emqx:get_config([log, throttling, time_window], 60))).
 
--spec allow(logger:level(), atom()) -> boolean().
-allow(debug, _Msg) ->
-    true;
-allow(_Level, Msg) when is_atom(Msg) ->
-    Seq = persistent_term:get(?SEQ_ID(Msg), undefined),
-    case Seq of
-        undefined ->
-            %% This is either a race condition (emqx_log_throttler is not started yet)
-            %% or a developer mistake (msg used in ?SLOG_THROTTLE/2,3 macro is
-            %% not added to the default value of `log.throttling.msgs`.
-            ?SLOG(info, #{
-                msg => "missing_log_throttle_sequence",
-                throttled_msg => Msg
-            }),
+-spec allow(atom()) -> boolean().
+allow(Msg) when is_atom(Msg) ->
+    case emqx_logger:get_primary_log_level() of
+        debug ->
             true;
-        SeqRef ->
-            ?IS_ALLOWED(SeqRef)
+        _ ->
+            do_allow(Msg)
     end.
 
 -spec start_link() -> startlink_ret().
@@ -132,6 +122,21 @@ code_change(_OldVsn, State, _Extra) ->
 %% internal functions
 %%--------------------------------------------------------------------
 
+do_allow(Msg) ->
+    case persistent_term:get(?SEQ_ID(Msg), undefined) of
+        undefined ->
+            %% This is either a race condition (emqx_log_throttler is not started yet)
+            %% or a developer mistake (msg used in ?SLOG_THROTTLE/2,3 macro is
+            %% not added to the default value of `log.throttling.msgs`.
+            ?SLOG(info, #{
+                msg => "missing_log_throttle_sequence",
+                throttled_msg => Msg
+            }),
+            true;
+        SeqRef ->
+            ?IS_ALLOWED(SeqRef)
+    end.
+
 maybe_add_dropped(Msg, Dropped, DroppedAcc) when Dropped > 0 ->
     DroppedAcc#{Msg => Dropped};
 maybe_add_dropped(_Msg, _Dropped, DroppedAcc) ->

apps/emqx/test/emqx_log_throttler_SUITE.erl

@@ -64,6 +64,10 @@ init_per_testcase(t_throttle_add_new_msg, Config) ->
     [?THROTTLE_MSG] = Conf = emqx:get_config([log, throttling, msgs]),
     {ok, _} = emqx_conf:update([log, throttling, msgs], [?THROTTLE_MSG1 | Conf], #{}),
     Config;
+init_per_testcase(t_throttle_debug_primary_level, Config) ->
+    ok = snabbkaffe:start_trace(),
+    Level = emqx_logger:get_primary_log_level(),
+    [{prev_log_level, Level} | Config];
 init_per_testcase(_TC, Config) ->
     ok = snabbkaffe:start_trace(),
     Config.
@@ -76,6 +80,9 @@ end_per_testcase(t_update_time_window, _Config) ->
     ok = snabbkaffe:stop(),
     {ok, _} = emqx_conf:update([log, throttling, time_window], ?TIME_WINDOW, #{}),
     ok;
+end_per_testcase(t_throttle_debug_primary_level, Config) ->
+    ok = snabbkaffe:stop(),
+    ok = emqx_logger:set_primary_log_level(?config(prev_log_level, Config));
 end_per_testcase(_TC, _Config) ->
     ok = snabbkaffe:stop().
 
@@ -88,18 +95,14 @@ t_throttle(_Config) ->
         begin
             %% Warm-up and block to increase the probability that next events
             %% will be in the same throttling time window.
-            lists:foreach(
-                fun(_) -> emqx_log_throttler:allow(warning, ?THROTTLE_MSG) end,
-                lists:seq(1, 100)
-            ),
-            {ok, _} = ?block_until(
-                #{?snk_kind := log_throttler_dropped, throttled_msg := ?THROTTLE_MSG}, 5000
+            {_, {ok, _}} = ?wait_async_action(
+                events(?THROTTLE_MSG),
+                #{?snk_kind := log_throttler_dropped, throttled_msg := ?THROTTLE_MSG},
+                5000
             ),
 
-            ?assert(emqx_log_throttler:allow(warning, ?THROTTLE_MSG)),
-            ?assertNot(emqx_log_throttler:allow(warning, ?THROTTLE_MSG)),
-            %% Debug is always allowed
-            ?assert(emqx_log_throttler:allow(debug, ?THROTTLE_MSG)),
+            ?assert(emqx_log_throttler:allow(?THROTTLE_MSG)),
+            ?assertNot(emqx_log_throttler:allow(?THROTTLE_MSG)),
             {ok, _} = ?block_until(
                 #{
                     ?snk_kind := log_throttler_dropped,
@@ -115,11 +118,11 @@ t_throttle(_Config) ->
 t_throttle_add_new_msg(_Config) ->
     ?check_trace(
         begin
-            ?block_until(
+            {ok, _} = ?block_until(
                 #{?snk_kind := log_throttler_new_msg, throttled_msg := ?THROTTLE_MSG1}, 5000
             ),
-            ?assert(emqx_log_throttler:allow(warning, ?THROTTLE_MSG1)),
-            ?assertNot(emqx_log_throttler:allow(warning, ?THROTTLE_MSG1)),
+            ?assert(emqx_log_throttler:allow(?THROTTLE_MSG1)),
+            ?assertNot(emqx_log_throttler:allow(?THROTTLE_MSG1)),
             {ok, _} = ?block_until(
                 #{
                     ?snk_kind := log_throttler_dropped,
@@ -134,15 +137,15 @@ t_throttle_add_new_msg(_Config) ->
 
 t_throttle_no_msg(_Config) ->
     %% Must simply pass with no crashes
-    ?assert(emqx_log_throttler:allow(warning, no_test_throttle_msg)),
-    ?assert(emqx_log_throttler:allow(warning, no_test_throttle_msg)),
+    ?assert(emqx_log_throttler:allow(no_test_throttle_msg)),
+    ?assert(emqx_log_throttler:allow(no_test_throttle_msg)),
     timer:sleep(10),
     ?assert(erlang:is_process_alive(erlang:whereis(emqx_log_throttler))).
 
 t_update_time_window(_Config) ->
     ?check_trace(
         begin
-            ?wait_async_action(
+            {_, {ok, _}} = ?wait_async_action(
                 emqx_conf:update([log, throttling, time_window], <<"2s">>, #{}),
                 #{?snk_kind := log_throttler_sched_refresh, new_period_ms := 2000},
                 5000
@@ -153,10 +156,42 @@ t_update_time_window(_Config) ->
         []
     ).
 
+t_throttle_debug_primary_level(_Config) ->
+    ?check_trace(
+        begin
+            ok = emqx_logger:set_primary_log_level(debug),
+            ?assert(lists:all(fun(Allow) -> Allow =:= true end, events(?THROTTLE_MSG))),
+
+            ok = emqx_logger:set_primary_log_level(warning),
+            {_, {ok, _}} = ?wait_async_action(
+                events(?THROTTLE_MSG),
+                #{?snk_kind := log_throttler_dropped, throttled_msg := ?THROTTLE_MSG},
+                5000
+            ),
+            ?assert(emqx_log_throttler:allow(?THROTTLE_MSG)),
+            ?assertNot(emqx_log_throttler:allow(?THROTTLE_MSG)),
+            {ok, _} = ?block_until(
+                #{
+                    ?snk_kind := log_throttler_dropped,
+                    throttled_msg := ?THROTTLE_MSG,
+                    dropped_count := 1
+                },
+                3000
+            )
+        end,
+        []
+    ).
+
 %%--------------------------------------------------------------------
 %% internal functions
 %%--------------------------------------------------------------------
 
+events(Msg) ->
+    events(100, Msg).
+
+events(N, Msg) ->
+    [emqx_log_throttler:allow(Msg) || _ <- lists:seq(1, N)].
+
 module_exists(Mod) ->
     case erlang:module_loaded(Mod) of
         true ->

rel/i18n/emqx_conf_schema.hocon

@@ -480,7 +480,8 @@ desc_log_throttling.label:
 
 desc_log_throttling.desc:
 """Log throttling feature reduces the number of potentially flooding logged events by
-dropping all but the first event within a configured time window."""
+dropping all but the first event within a configured time window.
+The throttling is automatically disabled if `console` or `file` log level is set to debug."""
 
 log_throttling_time_window.desc:
 """For throttled messages, only log 1 in each time window."""