How to ensure message delivery?

Question

How do you deliver messages using Pika ? By default, it will not provide you with an error message if the message was not delivered successfully.

In this example, several messages may be sent before pika confirms that the connection has been disconnected.

import pika connection = pika.BlockingConnection(pika.ConnectionParameters( host='localhost')) channel = connection.channel() channel.queue_declare(queue='hello') for index in xrange(10): channel.basic_publish(exchange='', routing_key='hello', body='Hello World #%s!' % index) print('Total Messages Sent: %s' % x) connection.close() 

Answer 1

When using Pika, the channel.confirm_delivery() flag must be set before publishing messages. It is important that Pika confirms that each message was sent successfully before sending the next message. However, this will increase the time required to send RabbitMQ messages, since delivery must be confirmed before the program can continue the next message.

 channel.confirm_delivery() try: for index in xrange(10): channel.basic_publish(exchange='', routing_key='hello', body='Hello World #%s!' % index) print('Total Messages Sent: %s' % x) except pika.exceptions.ConnectionClosed as exc: print('Error. Connection closed, and the message was never delivered.') 

basic_publish will return a Boolean value depending on whether the message was sent or not. But it is important to catch potential exceptions if the connection is closed during transmission and handled accordingly. As in those cases, the exception interrupts the program flow.