Preface

This book, the Message Queue Technical Overview, provides an introduction to the technology, concepts, architecture, capabilities, and features of the Message Queue messaging service.

As such, this book provides the foundation for other books within the Message Queue documentation set, and should be read first.

This preface consists of the following sections:

Who Should Use This Book
Before You Read This Book
How This Book Is Organized
Documentation Conventions
Related Documentation
Documentation, Support, and Training
Documentation Accessibility

Who Should Use This Book

This guide is meant for application developers, administrators, and other parties who plan to use the Message Queue product or who wish to understand the technology, concepts, architecture, capabilities, and features of the product. In the context of Message Queue:

An application developer is responsible for writing Message Queue client applications that use the Message Queue service to exchange messages with other client applications.
An administrator is responsible for setting up and managing a Message Queue messaging service.

This book does not assume any knowledge of messaging systems or the Java Message Service (JMS) specification, which is implemented by the Message Queue service.

Before You Read This Book

There are no prerequisites to this book. You should read this book to gain an understanding of basic Message Queue concepts and technology before reading the Message Queue developer and administration guides.

How This Book Is Organized

This guide is designed to be read from beginning to end; each chapter builds on information contained in earlier chapters. The following table briefly describes the contents of each chapter.

Chapter	Description
Chapter 1, "Messaging Systems: An Introduction"	Introduces messaging middleware technology, discusses the JMS standard, and describes the Message Queue service implementation of that standard.
Chapter 2, "Client Programming Model"	Describes the JMS programming model and how you can use the Message Queue client runtime to create JMS clients. Describes runtime support for C++ clients and for the transport of SOAP messages.
Chapter 3, "The Message Queue Broker"	Discusses administrative tasks and tools and describes broker services used to configure connections, routing, persistence, security, and monitoring.
Chapter 4, "Broker Clusters"	Discusses the architecture and use of Message Queue broker clusters.
Chapter 5, "Message Queue and Java EE"	Explores the ramifications of implementing JMS support in a Java EE platform environment.
Appendix A, "Message Queue Implementation of Optional JMS Functionality"	Describes how the Message Queue product handles JMS optional items.
Appendix B, "Message Queue Features"	Lists Message Queue features, summarizes steps needed to implement these, and provides reference for further information.
Glossary	Provides information about terms and concepts you might encounter while using Message Queue.

Documentation Conventions

This section describes the following conventions used in Message Queue documentation:

Typographic Conventions
Symbol Conventions
Shell Prompt Conventions
Directory Variable Conventions

Typographic Conventions

The following table describes the typographic conventions that are used in this book.

Typeface	Meaning	Example
`AaBbCc123`	The names of commands, files, and directories, and onscreen computer output	Edit your `.login` file. Use `ls` `a` to list all files. `machine_name% you have mail.`
`AaBbCc123`	What you type, contrasted with onscreen computer output	`machine_name%` `su` `Password:`
aabbcc123	Placeholder: replace with a real name or value	The command to remove a file is `rm` filename.
AaBbCc123	Book titles, new terms, and terms to be emphasized	Read Chapter 6 in the User's Guide. A cache is a copy that is stored locally. Do not save the file. Note: Some emphasized items appear bold online.

Symbol Conventions

The following table explains symbols that might be used in this book.

Symbol	Description	Example	Meaning
`[ ]`	Contains optional arguments and command options.	`ls [-l]`	The `-l` option is not required.
`{ \| }`	Contains a set of choices for a required command option.	`-d {y\|n}`	The `-d` option requires that you use either the `y` argument or the `n` argument.
`${ }`	Indicates a variable reference.	`${com.sun.javaRoot}`	References the value of the `com.sun.javaRoot` variable.
-	Joins simultaneous multiple keystrokes.	Control-A	Press the Control key while you press the A key.
+	Joins consecutive multiple keystrokes.	Ctrl+A+N	Press the Control key, release it, and then press the subsequent keys.
>	Indicates menu item selection in a graphical user interface.	File > New > Templates	From the File menu, choose New. From the New submenu, choose Templates.

Shell Prompt Conventions

The following table shows the conventions used in Message Queue documentation for the default UNIX system prompt and superuser prompt for the C shell, Bourne shell, Korn shell, and for the Windows operating system.

Shell	Prompt
C shell on UNIX, Linux, or AIX	machine-name`%`
C shell superuser on UNIX, Linux, or AIX	machine-name`#`
Bourne shell and Korn shell on UNIX, Linux, or AIX	`$`
Bourne shell and Korn shell superuser on UNIX, Linux, or AIX	`#`
Windows command line	`C:\>`

Directory Variable Conventions

Message Queue documentation makes use of three directory variables; two of which represent environment variables needed by Message Queue. (How you set the environment variables varies from platform to platform.)

The following table describes the directory variables that might be found in this book and how they are used. Some of these variables refer to the directory mqInstallHome, which is the directory where Message Queue is installed to when using the installer or unzipped to when using a zip-based distribution.

Note:

In this book, directory variables are shown without platform-specific environment variable notation or syntax (such as $IMQ_HOME on UNIX). Non-platform-specific path names use UNIX directory separator (/) notation.

Variable Description

Variable	Description
`IMQ_HOME`	The Message Queue home directory: For installations of Message Queue bundled with GlassFish Server, `IMQ_HOME` is as-install-parent`/mq`, where as-install-parent is the parent directory of the GlassFish Server base installation directory, `glassfish3` by default. For installations of Open Message Queue, `IMQ_HOME` is mqInstallHome`/mq`.
`IMQ_VARHOME`	The directory in which Message Queue temporary or dynamically created configuration and data files are stored; `IMQ_VARHOME` can be explicitly set as an environment variable to point to any directory or will default as described below: For installations of Message Queue bundled with GlassFish Server, `IMQ_VARHOME` defaults to as-install-parent`/glassfish/domains/domain1/imq`. For installations of Open Message Queue, `IMQ_HOME` defaults to mqInstallHome`/var/mq`.
`IMQ_JAVAHOME`	An environment variable that points to the location of the Java runtime environment (JRE) required by Message Queue executable files. By default, Message Queue looks for and uses the latest JDK, but you can optionally set the value of `IMQ_JAVAHOME` to wherever the preferred JRE resides.

IMQ_HOME

The Message Queue home directory:

For installations of Message Queue bundled with GlassFish Server, IMQ_HOME is as-install-parent/mq, where as-install-parent is the parent directory of the GlassFish Server base installation directory, glassfish3 by default.
For installations of Open Message Queue, IMQ_HOME is mqInstallHome/mq.

IMQ_VARHOME

The directory in which Message Queue temporary or dynamically created configuration and data files are stored; IMQ_VARHOME can be explicitly set as an environment variable to point to any directory or will default as described below:

For installations of Message Queue bundled with GlassFish Server, IMQ_VARHOME defaults to as-install-parent/glassfish/domains/domain1/imq.
For installations of Open Message Queue, IMQ_HOME defaults to mqInstallHome/var/mq.

IMQ_JAVAHOME

An environment variable that points to the location of the Java runtime environment (JRE) required by Message Queue executable files. By default, Message Queue looks for and uses the latest JDK, but you can optionally set the value of IMQ_JAVAHOME to wherever the preferred JRE resides.

Related Documentation

The information resources listed in this section provide further information about Message Queue in addition to that contained in this manual. The section covers the following resources:

Message Queue Documentation Set
Java Message Service (JMS) Specification
JavaDoc
Example Client Applications
Online Help

Message Queue Documentation Set

The documents that constitute the Message Queue documentation set are listed in the following table in the order in which you might normally use them. These documents are available through the Oracle GlassFish Server documentation web site at http://www.oracle.com/technetwork/indexes/documentation/index.html.

Document	Audience	Description
Technical Overview	Developers and administrators	Describes Message Queue concepts, features, and components.
Release Notes	Developers and administrators	Includes descriptions of new features, limitations, and known bugs, as well as technical notes.
Administration Guide	Administrators, also recommended for developers	Provides background and information needed to perform administration tasks using Message Queue administration tools.
Developer's Guide for Java Clients	Developers	Provides a quick-start tutorial and programming information for developers of Java client programs using the Message Queue implementation of the JMS or SOAP/JAXM APIs.
Developer's Guide for C Clients	Developers	Provides programming and reference documentation for developers of C client programs using the Message Queue C implementation of the JMS API (C-API).
Developer's Guide for JMX Clients	Administrators	Provides programming and reference documentation for developers of JMX client programs using the Message Queue JMX API.

Java Message Service (JMS) Specification

The Message Queue message service conforms to the Java Message Service (JMS) application programming interface, described in the Java Message Service Specification. This document can be found at the URL http://www.oracle.com/technetwork/java/jms/index.html.

JavaDoc

JMS and Message Queue API documentation in JavaDoc format is included in Message Queue installations at IMQ_HOME/javadoc/index.html. This documentation can be viewed in any HTML browser. It includes standard JMS API documentation as well as Message Queue-specific APIs.

Example Client Applications

Message Queue provides a number of example client applications to assist developers.

Example Java Client Applications

Example Java client applications are included in Message Queue installations at IMQ_HOME/examples. See the README files located in this directory and its subdirectories for descriptive information about the example applications.

Example C Client Programs

Example C client applications are included in Message Queue installations at IMQ_HOME/examples/C. See the README files located in this directory and its subdirectories for descriptive information about the example applications.

Example JMX Client Programs

Example Java Management Extensions (JMX) client applications are included in Message Queue installations at IMQ_HOME/examples/jmx. See the README files located in this directory and its subdirectories for descriptive information about the example applications.

Online Help

Online help is available for the Message Queue command line utilities; for details, see "Command Line Reference" in Oracle GlassFish Server Message Queue Administration Guide. The Message Queue graphical user interface (GUI) administration tool, the Administration Console, also includes a context-sensitive help facility; for details, see "Administration Console Online Help" in Oracle GlassFish Server Message Queue Administration Guide.

Documentation, Support, and Training

The Oracle web site provides information about the following additional resources:

Documentation Accessibility

For information about Oracle's commitment to accessibility, visit the Oracle Accessibility Program website at http://www.oracle.com/pls/topic/lookup?ctx=acc&id=docacc.

Access to Oracle Support

Oracle customers have access to electronic support through My Oracle Support. For information, visit http://www.oracle.com/pls/topic/lookup?ctx=acc&id=info or visit http://www.oracle.com/pls/topic/lookup?ctx=acc&id=trs if you are hearing impaired.