RMQ consumer

consume.rb

#!/usr/bin/env/ruby
# frozen_string_literals: true
#
#
require 'bunny'
require 'pry'
require 'logger'

host = 'localhost'
vhost = '/'
queue = 'test1'
exchange = 'amq.topic'
user = 'user'
password = 'password'
sleep_time = 0.0
nack_ratio = 0.0
prefetch = 7000

logger = Logger.new($stdout)

conn = Bunny.new(:host => host, :vhost => vhost, :user => user, :password => password)
conn.start
ch = conn.create_channel
ch.prefetch(prefetch)
q = ch.queue(queue, :exclusive => false, :durable => true, :arguments => { "x-queue-mode": 'lazy'})
x = ch.topic(exchange, :durable => true)
ack_count = 0
nack_count = 0
q.bind(x)
puts "nack:    ack:"
begin
  q.subscribe(:manual_ack => true, :block => true) do |delivery_info, payload|
    if rand > nack_ratio
      ch.acknowledge(delivery_info.delivery_tag, false)
      ack_count += 1
    else
      ch.basic_nack(delivery_info.delivery_tag, false, true)
      sleep sleep_time
      nack_count+=1
    end

    print (nack_count.to_s + "       " + ack_count.to_s + "\r")
    $stdout.flush
  end
rescue SystemExit, Interrupt
  logger.info "shutting down"
  ch.maybe_kill_consumer_work_pool!
  conn.close
  conn.clean_up_on_shutdown
end