Java Message Service

Chapter 6. Guaranteed Messaging, Transactions, Acknowledgments, and Failures

We have been introducing the notion of guaranteed messaging in bits and pieces throughout the book. Until now, we have assumed that you would take our word that guaranteed messaging ensures that messages are faithfully delivered once-and-only-once to their intended consumers.

This chapter examines why guaranteed messaging works, and provides a thorough discussion of the subject. We will examine the message acknowledgment protocols that are part of guaranteed messaging, and how to use client acknowledgments in applications. We will explore the design patterns of JMS that enable you to build guaranteed messaging into applications, and discuss failure scenarios, the rules that apply to recovery, and how to deal with recovery semantics in a JMS application.

Guaranteed Messaging

Guaranteed messaging is more than just a mechanism for handling disconnected consumers. It is a crucial part of the messaging paradigm, and is the key to understanding the design of a distributed messaging system. There are three main parts to guaranteed messaging: message autonomy, store-and-forward, and the underlying message acknowledgment semantics.

Before we discuss the parts of guaranteed messaging, we need to review and define some new terms. A JMS client application uses the JMS API. Each JMS vendor provides an implementation of the JMS API on the client, which we call the client runtime . In addition to the client runtime, the ...