Getting "pika.exceptions.ConnectionClosed" error when using rabbitmq in python

Question

I use the hello world tutorial at: http://www.rabbitmq.com/tutorials/tutorial-two-python.html . worker.pyas follows

import pika
import time


connection = pika.BlockingConnection(pika.ConnectionParameters(
        host='localhost'))
channel = connection.channel()

channel.queue_declare(queue='task_queue', durable=True)
print ' [*] Waiting for messages. To exit press CTRL+C'

def callback(ch, method, properties, body):
    print " [x] Received %r" % (body,)
    time.sleep( body.count('.') )
    print " [x] Done"
    ch.basic_ack(delivery_tag = method.delivery_tag)

channel.basic_qos(prefetch_count=1)
channel.basic_consume(callback,
                      queue='task_queue')

channel.start_consuming()

I used this code for implementation in my work. Everything runs smoothly until a dot in the queue appears for which it throws an exception after printing[x] Done

Traceback (most recent call last):
  File "hullworker2.py", line 242, in <module>
    channel.basic_consume(callback,queue='test_queue2')
  File "/usr/local/lib/python2.7/dist-packages/pika/channel.py", line 211, in basic_consume
    {'consumer_tag': consumer_tag})])
  File "/usr/local/lib/python2.7/dist-packages/pika/adapters/blocking_connection.py", line 904, in _rpc
    self.connection.process_data_events()
  File "/usr/local/lib/python2.7/dist-packages/pika/adapters/blocking_connection.py", line 88, in process_data_events
    if self._handle_read():
  File "/usr/local/lib/python2.7/dist-packages/pika/adapters/blocking_connection.py", line 184, in _handle_read
    super(BlockingConnection, self)._handle_read()
  File "/usr/local/lib/python2.7/dist-packages/pika/adapters/base_connection.py", line 300, in _handle_read
    return self._handle_error(error)
  File "/usr/local/lib/python2.7/dist-packages/pika/adapters/base_connection.py", line 264, in _handle_error
    self._handle_disconnect()
  File "/usr/local/lib/python2.7/dist-packages/pika/adapters/blocking_connection.py", line 181, in _handle_disconnect
    self._on_connection_closed(None, True)
  File "/usr/local/lib/python2.7/dist-packages/pika/adapters/blocking_connection.py", line 232, in _on_connection_closed
    self._channels[channel]._on_close(method_frame)
  File "/usr/local/lib/python2.7/dist-packages/pika/adapters/blocking_connection.py", line 817, in _on_close
    self._send_method(spec.Channel.CloseOk(), None, False)
  File "/usr/local/lib/python2.7/dist-packages/pika/adapters/blocking_connection.py", line 920, in _send_method
    self.connection.send_method(self.channel_number, method_frame, content)
  File "/usr/local/lib/python2.7/dist-packages/pika/adapters/blocking_connection.py", line 120, in send_method
    self._send_method(channel_number, method_frame, content)
  File "/usr/local/lib/python2.7/dist-packages/pika/connection.py", line 1331, in _send_method
    self._send_frame(frame.Method(channel_number, method_frame))
  File "/usr/local/lib/python2.7/dist-packages/pika/adapters/blocking_connection.py", line 245, in _send_frame
    super(BlockingConnection, self)._send_frame(frame_value)
  File "/usr/local/lib/python2.7/dist-packages/pika/connection.py", line 1312, in _send_frame
    raise exceptions.ConnectionClosed
pika.exceptions.ConnectionClosed

I do not understand how the connection automatically closes between the process. The process runs fine for 100 messages in the queue, and then this error occurs. Any help was appreciated.

Answer 1

heartbeats. , , .

time.sleep( body.count('.') )

N . , heartbeat, , , , , .

time.sleep() connection.sleep(), "sleep" N , .

 sleep(duration)[source]

    A safer way to sleep than calling time.sleep() directly which will keep the adapter from ignoring frames sent from RabbitMQ. The connection will "sleep" or block the number of seconds specified in duration in small intervals.