added setting to flush redis if you feel like doing so in dev

config/initializers/01-redis.rb

@@ -2,7 +2,7 @@ require "#{Rails.root}/lib/discourse_redis"
 
 $redis = DiscourseRedis.new
 
-if Rails.env.development? && !ENV['DO_NOT_FLUSH_REDIS']
+if Rails.env.development? && ENV['DISCOURSE_FLUSH_REDIS']
   puts "Flushing redis (development mode)"
   $redis.flushall
 end

vendor/gems/message_bus/spec/lib/multi_process_spec.rb

@@ -30,7 +30,7 @@ describe MessageBus::ReliablePubSub do
 
   it 'gets every response from child processes' do
     pid = nil
-    Redis.new(:db => 10).flushall
+    Redis.new(:db => 10).flushdb
     begin
       pids = (1..10).map{spawn_child}
       responses = []