for instance, 10.times do |s| puts s end 0 1 2 3 4 5 6 7 8 9 => 10 is the arguments block run in async mode? I have this question b/c my program quit earily. i don't know if it's due to somewhat async operations. the code is like (connection to rabbitmq), conn = Bunny.new conn.start ch = conn.create_channel exchange = ch.fanout("myfanout",:durable => true) 100.times do |s| exchange.publish(s.to_s) end It can't publish the entire 100 items to the broker, just some items. Thanks.