Book Image

RabbitMQ Essentials. - Second Edition

By : Lovisa Johansson, David Dossot
Book Image

RabbitMQ Essentials. - Second Edition

By: Lovisa Johansson, David Dossot

Overview of this book

RabbitMQ is an open source message queuing software that acts as a message broker using the Advanced Message Queuing Protocol (AMQP). This book will help you to get to grips with RabbitMQ to build your own applications with a message queue architecture. You’ll learn from the experts from CloudAMQP as they share what they've learned while managing the largest fleet of RabbitMQ clusters in the world. Following the case study of Complete Car, you’ll discover how you can use RabbitMQ to provide exceptional customer service and user experience, and see how a message queue architecture makes it easy to upgrade the app and add features as the company grows. From implementing simple synchronous operations through to advanced message routing and tracking, you’ll explore how RabbitMQ streamlines scalable operations for fast distribution. This book will help you understand the advantages of message queue architecture, including application scalability, resource efficiency, and user reliability. Finally, you’ll learn best practices for working with RabbitMQ and be able to use this book as a reference guide for your future app development projects. By the end of this book, you’ll have learned how to use message queuing software to streamline the development of your distributed and scalable applications.
Table of Contents (8 chapters)

Acknowledging messages

A message that is in transit between the broker and the consumer might get lost in the event of a connection failure, and important messages probably need to be retransmitted. Acknowledgments let the server and clients know when to retransmit messages.

There are two possible ways to acknowledge message delivery – once a consumer receives the message (an automatic acknowledgment, auto-ack), and when a consumer sends back an acknowledgment (explicit/manual acknowledge). With auto-ack, the message is acknowledged as soon as it leaves the queue (and is thereby removed from the queue). It is best to auto-ack when high message speeds are required, if the connections are reliable, and if lost messages aren't a concern.

Using manual acknowledgments on messages can have a performance impact on the system, compared to an automatic acknowledgment. If aiming for fast throughput, manual acknowledgments should be disabled, and auto acknowledgments should be used instead...