Gemfile

source "https://rubygems.org"

gem "bunny", :git => "git://github.com/ruby-amqp/bunny.git"

gistfile1.rb

#!/usr/bin/env ruby
require 'bunny'

Bundler.setup
connection = Bunny.new
connection.start

# ch = Bunny::Channel.new(connection, nil, Bunny::ConsumerWorkPool.new(8))
# ch.open

ch = connection.create_channel

def in_kb(n)
  (n / 1024).round(2)
end

q  = ch.queue("bunny.issues.119.limited", :durable => true, :arguments => {"x-max-length" => 100})
# q  = ch.queue("bunny.issues.119", :durable => true)

begin
  ts = []
  3.times do |i|
    q.subscribe(:block => false) do |delivery_info, metadata, payload|
      puts "Consumer #{delivery_info.consumer_tag} consumed #{in_kb(payload.bytesize)} KB"
    end
  end
  q.subscribe(:block => true) do |delivery_info, metadata, payload|
    puts "Consumer #{delivery_info.consumer_tag} consumed #{in_kb(payload.bytesize)} KB"
  end
rescue Interrupt => e
  puts "Terminating..."
  connection.close
end

publisher.rb

#!/usr/bin/env ruby
# -*- coding: utf-8 -*-
require 'bunny'

Bundler.setup
connection = Bunny.new
connection.start

ch = connection.channel
x  = ch.default_exchange

def multiplier(a, b)
  Range.new(a, b).to_a.sample
end

begin
  ts = []
  4.times do |i|
    t = Thread.new do
      loop do
        puts "Publishing on thread #{i}"
        10.times do |i|
          n   = multiplier(1, 1536) * 128
          msg = "Юникодный юникод такой юникодный #{i}" * n
          x.publish(msg, :routing_key => "bunny.issues.119.limited")
        end

        sleep (5.0 * rand)
      end
    end
    t.abort_on_exception = true
    ts << t
  end

  ts.each { |t| t.join }
rescue Interrupt => e
  puts "Terminating..."
  connection.close
end