From 2e955b0a5098aca35b0092f771ac80c0fe3efcac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-S=C3=A9bastien=20P=C3=A9dron?=
 <jean-sebastien@rabbitmq.com>
Date: Wed, 11 Aug 2021 15:23:29 +0200
Subject: [PATCH] Logging: Disable burst limit if the log level is set to
 `debug`

Otherwise, messages are being dropped, in particular during RabbitMQ
startup because of the amount of debug messages logged in that phase.

Burst limit is enabled again if the log level is set to `info` or
higher.
---
 deps/rabbit/src/rabbit_prelaunch_logging.erl | 22 +++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/deps/rabbit/src/rabbit_prelaunch_logging.erl b/deps/rabbit/src/rabbit_prelaunch_logging.erl
index 0dae47adde..c67b81cdcb 100644
--- a/deps/rabbit/src/rabbit_prelaunch_logging.erl
+++ b/deps/rabbit/src/rabbit_prelaunch_logging.erl
@@ -268,7 +268,7 @@ set_log_level(Level) ->
     %% of them to the new level.
     lists:foreach(
       fun
-          (#{id := Id, filters := Filters}) ->
+          (#{id := Id, filters := Filters, config := Config}) ->
               ?LOG_DEBUG(
                  "Logging: changing '~s' handler log level to ~s",
                  [Id, Level],
@@ -302,14 +302,18 @@ set_log_level(Level) ->
                                (Filter) ->
                                    Filter
                            end, Filters),
+              Config1 = adjust_burst_limit(Config, Level),
               logger:set_handler_config(Id, filters, Filters1),
+              logger:set_handler_config(Id, config, Config1),
               logger:set_handler_config(Id, level, Level),
               ok;
-          (#{id := Id}) ->
+          (#{id := Id, config := Config}) ->
               ?LOG_DEBUG(
                  "Logging: changing '~s' handler log level to ~s",
                  [Id, Level],
                  #{domain => ?RMQLOG_DOMAIN_GLOBAL}),
+              Config1 = adjust_burst_limit(Config, Level),
+              logger:set_handler_config(Id, config, Config1),
               logger:set_handler_config(Id, level, Level),
               ok
       end, logger:get_handler_config()),
@@ -1424,9 +1428,21 @@ adjust_log_levels(Handlers) ->
                         fun(_, LvlA, LvlB) ->
                                 get_less_severe_level(LvlA, LvlB)
                         end, GeneralLevel, FilterConfig),
-              Handler#{level => Level}
+              Handler1 = Handler#{level => Level},
+              adjust_burst_limit(Handler1)
       end, Handlers).
 
+adjust_burst_limit(#{config := #{burst_limit_enable := _}} = Handler) ->
+    Handler;
+adjust_burst_limit(#{level := debug, config := Config} = Handler) ->
+    Config1 = Config#{burst_limit_enable => false},
+    Handler#{config => Config1};
+adjust_burst_limit(Handler) when is_map(Handler) ->
+    Handler.
+
+adjust_burst_limit(Config, Level) ->
+    Config#{burst_limit_enable => Level =/= debug}.
+
 -spec assign_handler_ids(#{handler_key() => logger:handler_config()}) ->
     [logger:handler_config()].